Fluid flow control valve

ABSTRACT

A fluid flow control valve within a pop-up sprinkler arrests fluid flow through a riser of the pop-up sprinkler under abnormal flow conditions, such as when the riser is broken or a sprinkler head is removed from the riser. The riser, which is movable relative to a housing of the pop-up sprinkler, is attached to a sprinkler head which distributes water to the surrounding area. A valve seat device is disposed within the riser. A stopper is positioned within a valve passageway defined by the valve seat device. The stopper selectively engages the valve seat to inhibit water flow through the riser under abnormal flow conditions. A biasing device prevents the stopper from engaging with the valve seat under normal flow conditions. 
     A fluid flow control valve assembly within a swing joint of an irrigation system includes a first within a first elbow fitting and a second valve within a second elbow fitting. The first and second elbow fittings are movable relative to each other and together form the swing joint. Each valve includes a valve seat device and a stopper positioned within a valve passageway defined by the valve seat device. A biasing device positioned between the stoppers of the first and second valves prevents the second stopper from seating against the second valve seat under normal flow conditions.

RELATED CASE

This application is a continuation-in-part application of pending U.S.application Ser. No. 09/162,343, filed Sep. 28, 1998, which is acontinuation-in-part of U.S. application Ser. No. 09/151,618, filed Sep.11, 1998, which is a continuation-in-part of U.S. application Ser. No.09/081,960, filed May 19, 1998, which claims the benefit of priorityunder 35 U.S.C. § 119(e) of provisional U.S. application Ser. No.60/068,575, filed on Dec. 23, 1997.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a fluid control system, and inparticular to a fluid flow control valve. In one application, the fluidflow control valve can check the free flow of water from a broken ordamaged riser of an overhead irrigation system.

2. Description of Related Art

Overhead irrigation systems often incorporate water spray devices (e.g.,sprinkler heads) mounted on risers. Risers can either be fixed ormovable, e.g., pop-up type sprinklers. A riser supports a sprinkler somedistance above the ground, e.g., a few inches to several feet high. Atthis elevated position, the sprinkler has an enlarged spray pattern andirrigates a larger area than if the sprinkler were positioned closer tothe ground. Riser mounted sprinklers also accommodate crops of varyingheights.

Risers are pipes or conduits, typically made of plastic such aspolyvinylchloride (“PVC”), copper, brass, or galvanized steel. In manyirrigation systems, the riser extends upward from a fitting of theirrigation system, such as from a “T” or an elbow juncture, locatedunder ground. In such an arrangement, water flows from a subterraneanirrigation pipe through the riser to the sprinkler. In a pop-up typesprinkler, a movable riser extends from a housing when the sprinkler isin use. This enables a sprinkler head attached to an end of the riser torise to a predetermined height to deliver fluid to the surrounding area.

While the use of a riser-mounted sprinkler head enlarges the areairrigated by the sprinkler, the riser is susceptible to mechanicaldamage because it extends above ground in an exposed position. Becausetypically no external structure braces or buttresses the riser, theriser can be broken (e.g., severed) or otherwise damaged (e.g., theft,vandalism, etc.), resulting most often in an open, free-flowing outlet.In addition, if the sprinkler head is removed from the riser, fluid willflow freely from the riser.

When a riser is broken or the sprinkler head is removed, water cannot beproperly distributed through the sprinkler head. The rate of water flowincreases without the restricting back pressure provided by thesprinkler, such that a large stream of water projects above the brokenriser. The resulting water geyser impacts against a relatively smallground surface. Serious flooding and erosion consequently results in asmall area, while the remainder of the area normally irrigated by thesprinkler goes unwatered. A significant amount of water is wasted as theresult of the unrestricted flow through the broken riser, andsubstantial soil erosion can occur.

In addition, the water fountain gushing from the broken riser also canpose a serious highway problem if the water sprays onto highway lanes,or if the resulting water and soil run-off flows onto the highway.Numerous automobile accidents occur each year due to broken irrigationsystem risers.

While valves exist in the prior art for control of fluid flow ingeneral, many such valves are inappropriate for restricting the flow ofirrigation water through a riser with a free-flowing outlet, e.g. abroken or damaged riser, or a riser without a sprinkler head.Additionally, high volume farm irrigation systems introduce specialneeds for flow control. Prior valves are overly complicated andexpensive for application to farm irrigation systems, which utilizehundreds of riser-mounted sprinklers. Some devices which have beenimplemented for stanching the unrestricted flow of irrigation water haveproven unreliable, often failing to stop or even slow the rate of waterflow when a riser breaks or other failure occurs. Other prior devicesare too sensitive, shutting down water flow to undamaged risers.

In addition, when prior devices do function to stop the flow of waterthrough a broken riser, the broken sprinkler often remains undetectedfor days, leaving the area surrounding the broken sprinkler unwatered.This danger is especially true of farm irrigation, where a single brokenriser in a large field with many sprinklers could easily escape noticefor many days, damaging crops in the vicinity.

Further deficiencies in prior devices include an inability of thesedevices to cope with transient flow conditions. For instance, the priordevices may prematurely shut off the valve in response to thecombination of air and water in the system that often occurs when thesystem is first turned on. In addition, prior devices often includeimproperly restrained components which vibrate and wear under normalflow conditions.

Prior devices also have close fitting parts which are subject tocorrosion. As a result, the small space between the parts cannot bemaintained as corrosion, scale, debris, etc., often fill the spacebetween the closely fit parts, and the device is likely to malfunction.For example, in a prior valve, a disc or poppet is shaped and sized tohave a close fit with the valve seat in order to arrest fluid flow underabnormal flow conditions. Upon corrosion, however, the disc or poppetwill not properly seal the valve seat, thereby allowing fluid flowwithin the valve. Under some conditions, such corrosion, scaleformation, or like collected debris will prevent the valve disc orpoppet from moving at all.

A need therefore exists for a simple, inexpensive yet reliableirrigation control valve which allows water to flow to an operationalsprinkler, but restricts the water flow through a free-flowing outlet ofthe riser. Ideally, such a valve should allow detection of the brokenriser or missing sprinkler head, even when the flow through the riser isessentially shut off

SUMMARY OF THE INVENTION

The present fluid flow control valve is simply structured yet reactsonly to the presence of an abnormal flow condition through the systemwhich is indicative of a mechanical system failure (e.g., an open pipe,a removed or stolen sprinkler head, a broken riser, etc.). Under normalflow conditions, the valve remains open. This is true for bothsteady-state and transient flow conditions. Thus, during transient flow,which occurs when the system is initiated, the valve stays open eventhough the flow rate through the valve may momentarily exceed a flowrate which is indicative of an abnormal condition. The valve does notprematurely close.

In one mode, the fluid flow control device includes a valve seatdefining the passageway therethrough and a movable stopper thatselectively cooperates with the valve seat to at least substantiallyclose the passageway. A rod is positioned at least in part between thestopper and the valve seat, and is movable relative to the stopper. Therod prevents the stopper from seating against the valve during bothsteady-state and transient normal flow conditions. Therefore, evenduring transient normal flow conditions, the rod prevents the stopperfrom seating against the valve seat.

The fluid flow control valve does not have any close fitting parts,thereby reducing the likelihood of valve malfunction. In addition, fluidcan flow through the support to spin or agitate the stopper. Agitationof the stopper prevents build up beneath the stopper of sediment anddebris.

In accordance with another aspect of the present invention, a fluid flowdevice includes a fitting having a first port and a second port. A firstpassageway extends from the first port and a second passageway extendsfrom the second port. Between the first and second passageways is avalve seat, which defines a valve passageway. A stopper is positionedwithin the valve passageway, and is movable between an open positionrelative to the valve seat when fluid flows in a direction from thefirst port toward the second port, and a closed position when fluidflows in a direction from the second port toward the first port. Thestopper includes a compressible sealing member, which is positionedaround a portion of the stopper, to seat against the valve seat when thestopper is in the closed position. Additionally, the stopper includes avalve element which is located away from the valve seat when the stopperis in the open position and which seats against the valve seat when thestopper is in the closed position. The sealing member is located arounda portion of the valve element.

In accordance with a further aspect of the present invention, a fluidflow control device includes a valve seat device having a valve seat anda stopper positioning device disposed to one side of the valve seat. Astopper, which includes a valve element and a stem, cooperates with thevalve seat. The stopper is located relative to the valve seat devicesuch that a flared portion of the stem of the stopper is located on oneside of the valve seat and the valve element is located on the otherside of the valve seat. The stopper is movable between an open positionin which the valve element is located away from the valve seat and aclosed position in which the valve element is seated against the valveseat.

An additional aspect of the present invention includes a pop-upsprinkler having a housing, a pop-up riser at least partially disposedwithin the housing and movable relative to the housing. A valve seat iswithin the riser. A stopper cooperates with the valve seat and has avalve element. The stopper is movable between a first position and asecond position in which the valve element seats against the valve seat.A biasing device prevents the valve element from seating against thevalve seat under normal flow conditions. In addition, the pop-upsprinkler includes a sprinkler head attached to the riser. A filterbetween the sprinkler head and the valve seat can be unitary with thebiasing device.

In accordance with yet another aspect of the present invention, a fluidflow device for a pop-up sprinkler having a housing and a riser disposedat least partially within the housing and movable relative to thehousing, includes a valve seat defining a valve passageway, and astopper positioned within the valve passageway. The valve seat device issized and shaped to fit within the riser. The stopper is movable betweenan open position and a closed position. A biasing device biases thestopper in the open position and prevents the stopper from seatingagainst the valve seat under normal flow conditions. The biasing devicecan be attached to a filter of the pop-up sprinkler, which is positionedwithin the riser.

In accordance with an additional aspect of the present invention, afluid flow control valve assembly includes a first fitting and a secondfitting. The first and second fittings cooperate with and are movablerelative to one another. Each fitting has a valve within the fitting.The valve includes a valve seat positioned within the fitting and astopper which is movable between an open position and a closed position.A biasing device is positioned between the stopper of the first fittingand the stopper of the second fitting. The biasing device biases atleast one of the stoppers in an open position under normal flowconditions.

A further aspect of the present invention involves a fluid flow controlvalve within a swing joint of an irrigation system having a first valveseat device, a second valve seat device, a first stopper and a secondstopper. Each valve seat device includes a valve seat. The first stoppercooperates with the first valve seat and the second stopper cooperateswith the second valve seat. Each stopper includes a valve element and astem, which had a flared portion. The first stopper is located relativeto the first valve seat device such that the flared portion of the stemis located on one side of the valve seat and the first valve element islocated on the other side of the valve seat. The second stopper islocated relative to the second valve seat device such that the flaredportion of the stem is located on one side of the valve seat and thesecond valve element is located on the other side of the valve seat. Afirst biasing device prevents the first valve element from seatingagainst the first valve seat under normal flow conditions, and a secondbiasing device prevents the second valve element from seating againstthe second valve seat under normal flow conditions.

In accordance with another aspect of the present invention, a fluid flowcontrol device includes a housing having a first portion adapted tocooperate with a fitting of a fluid delivery system and a second portionadapted to cooperate with a branch section of the fluid delivery system.A valve seat is located within the first portion of the housing. Astopper, which is positioned a distance away from the valve seat, ismovable between a first position, in which the stopper is located adistance away from the valve seat, and a second position, in which thestopper seats against the valve seat. Because the valve seat is locatedwithin the first portion of the housing, the fluid flow control valve ofthis design can continue to function even if the housing is severedbetween the first and second portions.

An additional aspect of the present invention involves a fluid flowcontrol valve that includes a fitting having an influent port and aneffluent port. A main passageway extends from the influent port and abranch passageway extends from the effluent port. In one embodiment, themain passageway and branch passageway may be normal to one another. Inother embodiments, the main and branch passageways may intersect atother angles. In addition, the main passageway can terminate at theintersection between the main and branch passageways, such as an elbowfitting, or it may continue past the intersection such as a T-fitting.

A support is fixed to a housing having a valve seat with a stopper beingpositioned between the support and the valve seat. Because the supportis fixed to the housing, system shock can be absorbed and transferred bythe support to the housing.

In addition, at least a portion of the support and stopper arepositioned generally within the main passageway under normal flowconditions. Placement of the support and stopper within the mainpassageway minimizes head loss within the branch passageway. The stopperis movable between an open position in which the stopper is located adistance away from the valve seat under normal flow conditions and aclosed position in which the stopper seats against the valve seat underabnormal flow conditions.

In accordance with an additional aspect of the present invention, afluid flow control device includes a housing having a valve seat and astopper within the housing. The stopper is movable between an openposition in which the stopper is located a distance away from the valveseat and a closed position in which the stopper seats against the valveseat. The housing is adapted to fit within a fitting of a fluid deliverysystem.

The housing includes a valve seat member which contains the valve seatand which is adapted to cooperate with the fitting of the fluid deliverysystem. The housing further includes a support fixed to the valve seatmember. The stopper is positioned between the valve seat member and thesupport.

In accordance with a further aspect of the present invention, a fluidflow control valve is disclosed for controlling flow through a fluiddelivery section and a fluid delivery device of a fluid delivery system.The valve includes a housing connected to a first end of the fluiddelivery section of the fluid delivery system. A valve seat is locatedwithin the housing between a first receptacle and a second receptacle. Akeeper is positioned downstream from a stopper, which is movable betweena first position located a distance away from the valve seat and asecond position seated against the valve seat. The keeper, which canvary in length, has a first end positioned in close proximity to thestopper and a second end positioned in close proximity to the fluiddelivery device. The keeper can comprise a plurality of rods stackedlengthwise within the fluid delivery system. Grooves spacedlongitudinally along the rod can facilitate in sizing the rod to fitwithin a fluid delivery section having a length less than the length ofthe rod.

In accordance with yet another aspect of the present invention, a methodfor controlling fluid flow through a fluid delivery system involvesproviding a valve between a primary line and a secondary line of thefluid delivery system. The valve includes a movable stopper whichselectively engages a valve seat to inhibit fluid flow through thesecondary line. The stopper is positioned within the fluid flow throughthe primary line in a normal location under normal flow conditions. Inthis normal location, the stopper ties near the valve seat and in aposition in which fluid flows on a side of the stopper opposite thesecondary line. The stopper is maintained in the normal location undernormal flow conditions. However, under abnormal flow conditions, thestopper is moved to a closed position. The stopper is seated against thevalve seat when in a closed position to inhibit fluid flow through thesecondary line under abnormal flow conditions. A fine stream of fluidcan be projected from the valve to indicate that the valve is closed.This fine stream of fluid signals that a fault condition has occurredand facilitates in identifying the location of the closed valve.

In accordance with a further aspect of the invention, a method forcontrolling fluid flow through a delivery system involves providing avalve between a source of fluid and an effluent port of the fluiddelivery system. The valve includes a movable stopper which selectivelyengages a valve seat to inhibit fluid flow through the effluent port. Astopper is positioned in an open position near the valve seat betweenthe source of fluid and the valve seat in a position which allows fluidto flow through a passageway defined by the valve seat. A biasing deviceis positioned at least partially between the stopper and the valve seatand generally in contact with the stopper during normal flow conditionssuch that there is relative movement between the biasing device and thestopper. The stopper is maintained in the open position under normalflow conditions. The stopper is moved to a closed position underabnormal flow conditions such that the stopper seats against the valveseat when in the closed position to inhibit fluid flow through theeffluent port under abnormal flow conditions. The biasing device can besized to correspond with the effective length between a fluid deliverydevice of the fluid delivery system and the stopper, when the stopper isin the open position. The valve of this design can be used in a numberof systems of various sizes because the biasing device can be easilysized to fit within the fluid delivery device and stopper.

An additional aspect of the present invention involves a valve assemblykit including a housing having a valve seat, a stopper adapted tocooperate with the valve seat and a plurality of rods adapted to besized to fit within a portion of the housing and a branch section of afluid delivery system. A cap which is releasably attachable to at leastone of the rods and configured to allow fluid to flow through the capmay also be included in the valve assembly kit. Each rod may have aplurality of grooves spaced longitudinally along the rod whereby thegrooves facilitate in breaking off a portion of the rod to size the rodto fit within the branch section of the fluid delivery system.Additionally, the plurality of rods can include at least two rods whichdiffer in length from one another.

In accordance with another aspect of the present invention, a valveincludes a fitting having an influent, at least one effluent port, avalve seat and a stopper. A main passageway extends from the influentport and a branch passageway extends from the main passageway to theeffluent port. The valve seat is located within the branch passageway.The stopper is movable between an open position relative to the valveseat under normal flow conditions and a closed position relative to thevalve seat. Further, at least a portion of the stopper is supported andpositioned generally within the main passageway of the fitting undernormal flow conditions.

In addition, the stopper includes a stem portion and a valve element.The valve element of the stopper is located away from the valve seatwhen the stopper is in the open position and is seated against the valveseat when the stopper is in the closed position.

In accordance with yet another aspect of the present invention, a fluidflow control device includes a valve seat device having a valve seat anda stopper, which is not attached to the valve seat device. The stopperincludes a valve element which is movable between a first position and asecond position. In the first position, the valve element is located adistance away from the valve seat, and in the second position, the valveelement seats against the valve seat. The valve element is preventedfrom seating against the valve seat under normal flow conditions by abiasing. In some instances, the biasing device will comprise a rod.

A further aspect of the present invention involves a fluid flow controldevice including a valve seat device having a valve seat and a stopperunattached to the valve seat. The stopper includes a valve element and astem with a flared portion. The stopper is located relative to the valveseat device such that the flared portion of the stem is located on oneside of the valve seat and the valve element is located on the otherside of the valve seat. The stopper is movable between an open positionin which the valve element is located away from the valve seat and aclosed position in which the valve element is seated against the valveseat.

In accordance with an additional aspect of the present invention, amethod for manufacturing a fluid flow device involves molding a valveseat device to have an inner passage and also molding a stopper to havea valve element which is larger than the inner passage. While at leastthe valve seat device is at a temperature above ambient, the valveelement is passed through the inner passage, and the valve seat deviceis cooled.

In accordance with still another aspect of the present invention, afluid flow control device includes a fitting having a first port and asecond port. A first passageway extends from the first port and secondpassageway extends from the second port. Between the first and secondpassageways is a valve seat. A stopper is positioned within the valveseat. The stopper is movable between an open position relative to thevalve seat when fluid flows in a direction from the first port towardthe second port and a closed position when fluid flows in a directionfrom the second port toward the first port. A portion of the stopper iswithin the valve passageway when the stopper is in the open position.

Various features of the above noted aspects of the invention can also beinterchanged, as will be readily apparent to those skilled in the art.In addition, further aspects, features, and advantages of the presentinvention will become apparent from the detailed description of thepreferred embodiments which follow.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of the invention will now be described withreference to the drawings of several embodiments of the present fluidflow control valve, which are intended to illustrate, but not to limitthe invention. The drawings contain the following figures:

FIG. 1 is a perspective view of a fluid flow control valve configured inaccordance with an embodiment of the present invention;

FIG. 2 is an exploded, perspective view of the fluid flow control valveof FIG. 1;

FIG. 3 is a left side elevational view of a fitting of the fluid flowcontrol valve of FIG. 2;

FIG. 4 is a top plan view of the fitting of FIG. 3;

FIG. 5 is a front elevational view of the fitting of FIG. 3;

FIG. 6 is a cross-sectional view of the fitting of FIG. 3 taken alongline 6—6 of FIG. 4;

FIG. 7 is a cross-sectional view of a cap of the fluid flow controlvalve of FIG. 2;

FIG. 8 is a perspective, cross-sectional view of the fluid flow controlvalve of FIG. 1 operating under normal flow conditions;

FIG. 9 is a perspective, cross-sectional view of the fluid flow controlvalve of FIG. 8 immediately after the riser is broken with water flowingthrough the fluid flow control valve under abnormal flow conditions;

FIG. 10 is a perspective, cross-sectional view of the fluid flow controlvalve of FIG. 9 in a closed position;

FIG. 11 is an exploded, perspective view of a fluid flow control valvein accordance with another preferred embodiment;

FIG. 12 is a cross-sectional view of the fluid flow control valve ofFIG. 11 under normal flow conditions;

FIG. 13 is a cross-sectional view of the fluid flow control valve ofFIG. 11 after it has reacted to abnormal flow conditions;

FIG. 14 is a cross-sectional view of a fluid flow control valve inaccordance with another preferred embodiment;

FIG. 15 is an exploded, cross-sectional view of the fluid flow controlvalve of FIG. 14;

FIG. 16a is a perspective, cross-sectional view of the valve cap of thefluid flow control valve of FIG. 14 shown in an upside-down positionrelative to the valve cap shown in FIG. 14;

FIG. 16b is a perspective view of the basket of the fluid flow controlvalve of FIG. 14;

FIG. 17 is an elevational view of the rod of the fluid flow controlvalve of FIG. 14;

FIG. 18a is a cross-sectional view of the rod of FIG. 17 taken alongline 18 a—18 a of FIG. 17;

FIG. 18b is a cross-sectional view of the rod of FIG. 17 taken alongline 18 b—18 b of FIG. 17;

FIGS. 19a and 19 b are cross-sectional views of the top portion of therod and cap of the fluid flow control valve of FIG. 14 in combinationwith a first type and a second type of sprinkler head connected to ariser;

FIG. 20 is a graph illustrating head loss versus flow rate through aflow control valve configured in accordance with the embodiment shown inFIG. 14;

FIG. 21 is an exploded, cross-sectional view of a fluid flow controlvalve in accordance with another preferred embodiment;

FIG. 22 is a bottom plan view of the valve seat member of the fluid flowcontrol valve of FIG. 21;

FIG. 23 is a cross-sectional view of the valve seat member of FIG. 24taken along line 23—23 of FIG. 22;

FIG. 24 is a bottom plan view of the basket of the fluid flow controlvalve of FIG. 21;

FIG. 25 is a cross-sectional view of the basket of FIG. 23 taken alongline 25—25 of FIG. 24;

FIG. 26 is a cross-sectional view of the fluid flow control valve ofFIG. 21 within a T-fitting;

FIG. 27 is a cross-sectional view of the fluid flow control valve ofFIG. 21 within an elbow fitting;

FIG. 28 is a cross-sectional view of another embodiment of a fluid flowcontrol valve operating under normal flow conditions;

FIG. 29 is a perspective, cross-sectional view of the fluid flow controlvalve of FIG. 28 immediately after the riser is broken with waterflowing through the fluid flow control valve under abnormal flowconditions;

FIG. 30 is a perspective, cross-sectional view of the fluid flow controlvalve of FIG. 29 in a substantially closed position;

FIG. 31 is a perspective, cross-sectional view of a further embodimentof a fluid flow control valve;

FIG. 32 is an exploded, perspective view of a fluid flow control valvein accordance with another preferred embodiment;

FIG. 33 is a cross-sectional view of the fluid flow control valve ofFIG. 32 operating under normal flow conditions;

FIG. 34 is a top plan view of the valve seat device of the fluid flowcontrol valve of FIG. 32;

FIG. 35 is a cross-sectional view of the valve seat device of FIG. 34taken along line 35—35 of FIG. 34;

FIG. 36 is a side view of the stopper of the fluid flow control valve ofFIG. 32;

FIG. 37 is a cross-sectional view of a stem of the stopper of FIG. 36taken along line 37—37 of FIG. 36;

FIG. 38 is a cross-sectional view of the fluid flow control valve ofFIG. 32 in a closed position;

FIG. 39 is a cross-sectional view of a fluid flow control valve inaccordance with an additional preferred embodiment, the valve being inan open position;

FIG. 40 is a cross-sectional view of an additional embodiment of a fluidflow control valve operating under normal flow conditions;

FIG. 41 is a cross-sectional view of the fluid flow control valve ofFIG. 40 in a closed position;

FIG. 42 is cross-sectional view of another embodiment of a fluid flowcontrol valve assembly under abnormal flow conditions with the valvebeing in a closed position;

FIG. 43 is an exploded, perspective view of the fluid flow control valveassembly of FIG. 42;

FIG. 44 is an enlarged, perspective cross-sectional view of the stopperof the fluid flow control valve of FIG. 42;

FIG. 45 is a cross-sectional view of a further embodiment of a fluidflow control valve in a pop-up sprinkler;

FIG. 46 is an exploded, cross-sectional view of the pop-up sprinkler andfluid flow control valve of FIG. 45;

FIG. 47 is a slightly reduced, cross-sectional view of the pop-upsprinkler with the fluid flow control valve of FIG. 45 under normal flowconditions when the sprinkler is in use;

FIG. 48 is a cross-sectional view of the pop-up sprinkler and the fluidflow control valve of FIG. 45 with the valve in a substantially closedposition under an abnormal flow condition;

FIG. 49 a cross-sectional view of an additional embodiment of a fluidflow control valve in a pop-up sprinkler when the sprinkler is not inuse;

FIG. 50 is a cross-sectional view of the fluid flow control valve ofFIG. 49 under normal flow conditions when the sprinkler is in use;

FIG. 51 is a cross-sectional view of the fluid flow control valve ofFIG. 49 in a substantially closed position under an abnormal flowcondition;

FIG. 52 is an exploded, perspective view of another variation of a fluidflow control valve assembly integrated into a swing joint of anirrigation system;

FIG. 53 is a cross-sectional view of the fluid flow control valveassembly of FIG. 52 under normal flow conditions;

FIG. 54 is a cross-sectional view of the fluid flow control valveassembly with a first valve in a substantially closed position; and

FIG. 55 is a cross-sectional view of the fluid flow control valveassembly with a second valve in a substantially closed position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates generally to fluid flow control valves forrestricting fluid flow rates. Those skilled in the art will readilyappreciate that the present invention may have application in a varietyof fluid delivery systems where fluid flow through a particular branchof the system should be maintained below a predetermined flow rate orshould be arrested if a mechanical failure occurs in a downstreamsection of the branch. While the following embodiments are described inthe context of irrigation systems, it will be understood that thestructures, methods and principles described herein are readilyapplicable to the restriction of fluid flow in other contexts. Theirrigation context, therefore, is merely an exemplary field of use.

FIGS. 1-10 illustrate a fluid control valve 10 configured in accordancewith a preferred embodiment of the present invention. The valve 10 canbe integrated into any of a variety of junctures. For example, butwithout limitation, the valve 10 can take the form of the illustratedT-joint, an elbow joint, a comer joint, or a swing joint (as illustratedin FIGS. 52-55 and described below). In this manner, the valve 10 can beemployed throughout an irrigation or other fluid delivery system.

With initial reference to FIG. 1, the control valve 10 is insertedbetween a pair of irrigation pipes 12, 14, which form a part of a largerirrigation system. The irrigation pipes 12, 14 can connect togethermultiple control valves to form at least a portion of the irrigationsystem.

A riser 16 desirably extends upwardly from the control valve 10 tosupport a sprinkler head 18 in an elevated position. As noted in the“Background” section above, the sprinkler provides diffuse distributionto irrigate a large area from its elevated position.

The valve 10 includes at least one influent port and at least oneeffluent port. In the illustrated embodiment, the valve 10 forms aT-junction with one influent port 20 in communication with an upstreamirrigation pipe 12, a first effluent port 22 communicating with theriser 16, and a second effluent port 24 communicating with a downstreamirrigation pipe 14.

As best seen in FIGS. 1 and 2, the valve 10 includes a fitting 26 whichis positioned between adjacent ends of the aligned irrigation pipes 12,14. A stopper or plug 28 operates within the fitting 26 to selectivelyarrest flow through the first effluent port 22 in the manner describedbelow.

In the illustrated embodiment, a cap 30 is attached to an upper end 32of the fitting 26 and defines, in part, the first effluent port 22. Thecap 30 also at least partially secures the stopper 28 within the fitting26. Together the fitting 26 and cap 30 define a valve housing.

Though in the illustrated embodiment the valve housing includes a twopiece construction—a fitting 26 and a cap 30—it is understood that thevalve 10 can comprise a unitary housing that includes the first effluentport as well as the influent port (as illustrated in FIG. 24). Theunitary housing can take the form of a single molded piece, or of twomolded pieces fused or welded together, e.g., by sonic welding. For suchan arrangement, a separate cap, such as that in the illustratedembodiment, would not be necessary.

The individual components of the valve 10 will now be described indetail. The valve 10 will be described in terms of the illustratedarrangement within the irrigation system with a water flow in ahorizontal direction between the influent port 20 and the secondeffluent port 24, and a water flow in the vertical direction through thefirst effluent port 22. The terms “horizontal” and “vertical,” ofcourse, depend on the chosen orientation of the valve 10 and are usedhere to simplify the description. Likewise, terms of orientation, suchas “above”, “below”, “upper” and “lower”, are used in the context of theillustrated embodiment; however, because other orientations arepossible, the present invention should not be limited to the illustratedorientation. Those skilled in the art will appreciate that otherorientations of the valve 10 also are possible.

With reference to FIGS. 3-6, the fitting 26 defines the influent port 20and the second effluent port 24. The fitting 26 desirably comprises aone-piece, molded PVC part. The influent port 20 is defined at anupstream end of the fitting 26, while the second effluent port 24 isdefined at an opposite downstream end of the fitting 26. In theillustrated embodiment, each of the ports 20, 24 has a generallycircular cross-sectional shape which is sized to receive an end of thecorresponding irrigation pipe 12, 14 (see FIG. 1) in a slip fit manner.It is understood, however, that the cross-sectional shape of the ports20, 24 can have any of a variety of shapes and sizes, and methods ofjoining the pipes, depending upon the shape of the conduits to bereceived.

A conventional bonding agent, such as, for example, a solvent-basedcement for PVC material, can be used to attached the fitting 26 onto theends of the irrigation pipes 12, 14 in a known manner. The ends of thefitting 26, however, can also include coupling structure thatinterconnects the fitting 26 to the irrigation pipes 12, 14. Forexample, the fitting 26 can be coupled to the pipes by a threadedconnection.

As seen in FIGS. 3-6, a primary passage 34 extends horizontally betweenthe ports 20, 24. The influent port 20, the second effluent port 24 andthe primary passage 34 desirably are aligned along a common primary flowaxis P_(A). As illustrated in FIG. 3, the inner diameters of the fitting26 at the influent port 20 and the second effluent port 24 are slightlylarger than the inner diameter in the primary passage 34. A step 36(FIG. 6) in diameter between the primary passage 34 and each port 20, 24provides a seat against which the irrigation pipes 12, 14 (FIG. 1) abutwhen completely slipped into the fitting 26.

The diameter of the inner surfaces of the irrigation pipes 12, 14 andthe primary passage 34 desirably match for a smooth transition betweenthe valve 10 and the pipes 12, 14. This construction reduces thepressure drop across the valve 10.

A branch or secondary passage 38 extends from the primary passage 34. Inthe illustrated embodiment, the branch passage 38 extends generallynormal to the primary flow axis P_(A) and defines a branch flow axisB_(A) therealong. The branch passage 38 terminates at the upper end 32.

In the illustrated embodiment, an external thread extends about theupper end 32 of the fitting 26. The external thread is sized tocooperate with an internal thread of the cap to secure the cap 30 to thefitting 26, as described below.

As best seen in FIGS. 3 and 6, the primary and branch passages 34, 38together define an internal cavity 40 within the fitting 26. The cavity40 is defined in part by a recess 42 that is formed in the fitting 26 onthe opposite side of the primary flow axis P_(A) from the branch passage38.

The recess 42 defines an extension of the cavity 40 below the primaryflow passage 34. The recess 42 desirably comprises a smoothly curvedsurface to minimize resistance to fluid flow, and is sized toaccommodate a substantial portion of fluid flow during normal flowconditions, as will be further defined below. In the illustratedembodiment, the recess 42 has hemispherical shape with an inner diametergenerally matching the inner diameter of the cylindrical primary passage34.

Desirably, the valve 10 includes a support for maintaining the stopper28 within the cavity 40. In particular, the support maintains thestopper 28 within a fluid flow path under normal flow conditions. Fluidthus flows around the stopper 28, as will be understood from thedescription below.

In the illustrated embodiment, a post 44 extends from roughly the centerof the recess 42 upwardly into the cavity 40, as best seen from FIG. 6.This post serves to support the stopper 28 within the cavity 40. Theupper end of the post 44 desirably terminates at even level or slightlybelow a bottom surface portion 46 of the primary passage 34.

One or more straightening vanes 48 extend into the primary passage 34downstream of the recess 42. At least one vane 48 advantageously extendscompletely across the primary passage 34 and is arranged substantiallyparallel to the primary flow axis P_(A).

In the illustrated embodiment, a pair of vanes 48 lie parallel to eachother. The vanes 48 extend across the primary passage 34 in the verticaldirection and are spaced relative to each other and to the sides of thepassage 34 to prevent the stopper 28 from escaping through the effluentport 24. The vanes 48 desirably present a thin profile to the waterflow, as seen in FIG. 5, but have a sufficient length (i.e., in adirection parallel to the primary flow axis P_(A)) to provide a flowstraightening effect of fluid flow passing through the vanes 48, as seenin FIGS. 3 and 6.

On the upstream side of the recess 42, an extension 50 extends at leastpartway into the primary passage 34 and is located between the influentport 20 and the recess 42. In the illustrated embodiment, the extension50 extends in the vertical direction from the bottom portion surface 46of the primary passage 34 toward the flow axis P_(A), and lies at anupstream edge of the recess 42. The vertical length of the extension 50advantageously is sufficient to prevent the stopper 28 from migratingtoward the influent port 20. In the illustrated embodiment, theextension 50 extends only partway across the primary passage 34. By suchan arrangement, the extension 50 impedes only a portion of the fluidflowing through the lower half of the passage 34.

Although not illustrated, at least one straightening vane can be used inthe place of the extension 50. If a second pair of straightening vaneswere used and were configured and arranged within the passage 34 inaccordance with the above-description, but on the upstream side of thebranch passage 38, the valve 10 would be bidirectional. That is, eitherend of the fitting 26 could function as the influent port or the secondeffluent port. It would not matter which direction the valve 10 wereinstalled.

The illustrated embodiment of the valve 10, however, is orientationsensitive and has a distinct influent port 20 and a distinct secondeffluent port 24. For this reason, the valve 10 desirably includesindicia that indicates the designed direction of fluid flow though theprimary passage 34 of the valve 10. In the illustrated embodiment, anarrow 52 (FIG. 3) on the surface of the fitting 26 indicates thisdesirable direction of flow through the primary passage 34 during normaloperation; however, other indicia, such as the designations “in” and“out” at the influent port 20 and the second effluent port 24,respectively, can be used as well.

The cap 30 is attached to the upper end 32 of the fitting 26 at theterminal end of the branch passage 38 to complete in principal the firsteffluent port 22. With reference to FIG. 7, a cross-section of the cap30 is shown. As with the primary and secondary passages 34, 38 of thefitting 26, the cap 30 desirably has a generally cylindrical shape foraesthetic purposes.

The cap 30 includes a lower receptacle 54 that engages with the fitting26. The lower receptacle 54 includes an internal thread that is sized tocooperate with the external threads of the fitting upper end 32.

The cap 30 also includes an upper receptacle 56, which desirably isthreaded and is sized to engage a corresponding riser 16. In theillustrated embodiment, the diameter d of the upper receptacle 56 issmaller than the diameter of the branch passage 38 (FIG. 6); however,the diameter of the upper receptacle 56 can match that of the lowerreceptacle 54 or can be larger than the diameter of the lower section54, depending upon the size of the riser 16.

In the illustrated embodiment, a valve seat 58 lies between the upperand lower receptacles 54, 56 within the valve cap 30. In this position,the valve seat 58 is located near the first effluent port 22 in theassembled valve 10, as described below. It is possible, however, for thevalve seat 58 to lie at other locations within the valve 10. Forinstance, the valve seat 58 can be arranged to lie at the intersectionbetween primary passage 34 and the branch passage 38, as well as at anyintermediate position within the branch passage 38, rather than at theupper end of the branch passage 38 as illustrated in FIG. 8.

As best seen in FIG. 7, the valve seat 58 comprises an annular ridge 60interposed between the upper receptacle 56 and the lower receptacle 54.The ridge 60 includes an annular inner face 62. The inner face 62defines a valve throat 64 between the upper and lower receptacles 54,56.

The valve throat 64 has a smaller diameter than the stopper 28. In theassembled valve 10, the valve throat 64 defines in part the firsteffluent port 32 of the fitting 26.

The ridge 60 desirably comprises a chamfer or facet 66 on the inlet sideof the valve throat 64 that forms a beveled transitions between theinner face 62 and a lower face 68 of the ridge 60.

As best understood from FIGS. 2 and 7 together, the valve seat 58 alsoincludes a gasket 70 that is interposed between the upper end 32 of thefitting 26 and the cap 30. The gasket 70 seats flush against the lowerface 68 of the ridge 60 within the assembled valve 10.

The gasket 70 desirably has an annular configuration with an outerdiameter larger than the diameter of the branch passage 38 and smallerthan an inner diameter of the cap's lower receptacle 54. In this manner,the peripheral edge of the gasket 70 is captured between the upper end32 of the fitting 26 and the lower face 68 of the ridge 60 to secure thegasket 70 in this interposed position.

The inner diameter of the gasket 70 desirably is larger than thediameter of the valve throat 64 and smaller than a diameter of anannular ridge 72 (FIG. 7) defined at the intersection between thechamfer 66 and the lower face 68 of the ridge 60. In this manner, theinner periphery of the gasket 70 is sized to extend at least partiallybelow the facet 66 of the valve seat 58.

The gasket 70 advantageously is made of a resilient material capable ofelastically deforming around a portion of the stopper's surface.Appropriate materials for the gasket 70 include rubber and polyethylene,such as are typically used for washers in plumbing and irrigation pipesealing applications.

The valve 10 also desirably comprises at least one telltale port locatedat or near the first effluent port 22 for allowing a small stream offluid to pass through the effluent port 22 when the valve 10 is closedduring abnormal flow conditions. In the illustrated embodiment, as bestseen in FIG. 2, the valve 10 includes a plurality of telltale portswhich take the form of slots or notches 74 formed along the innerperiphery 60 of the gasket 70. Each notch 74 exposes a portion of thefacet 66. The notches 74 are evenly disposed about the inner peripheryof the gasket 74, being spaced apart by 90° in the illustratedembodiment; however, the notches can be spaced apart at other intervals.For instance, twelve notches can be spaced apart by 30°, or eightnotches can be spaced a part by 45°.

The telltale port can also take other forms. For instance, the telltaleport can comprise an auxiliary passage which extends either through oradjacent to the first effluent port 22, independent of the valve throat64. In this arrangement, the auxiliary passage would communicate withthe branch passage 38 at a location not sealed by the stopper 28 underabnormal flow conditions.

As understood from FIG. 2, the stopper 28 in the illustrated embodimentis a free-floating spherically-shaped ball; however, other shapes anddegrees of freedom of the stopper are also possible. For instance, thestopper can be valve plate which moves along a defined travel pathbetween a normally open position—with the stopper supported within thecavity 40—and a closed position seated against the valve seat 58.

In the illustrated embodiment, the stopper 28 has a diameter larger thanthat of the valve throat 64, but sufficiently smaller than the cavity40, and particularly smaller than the diameter of the branch passage 38,so as to move freely into and through the branch passage 38. Moreparticularly, the stopper 28 is sized so as to freely move from itsillustrated position on top the post 44 to a position seated against thevalve seat 58 (see FIG. 10) in response to abnormal flow conditions.

The stopper 28 desirably is sufficiently heavy to counteract any liftingforces inherent within the turbulent flow through the cavity 40 undernormal operating conditions, but sufficiently light to be seated by aresultant pressure differential occurring on opposite sides of thestopper 28 under abnormal flow conditions, as described below.

The stopper 28 desirably is made of glass and takes a form similar to amarble. For normal operating water pressures within the range from about5 pounds per square inch (psi) (34.5×10³ Pa) to 90 psi (620.6×10³ Pa),glass has a suitable density to meet the weight and size requirementsdiscussed above. Glass also resists algae growth and does not rust,which are particularly advantageous characteristics for use inirrigation applications. Other materials also are possible, however. Forexample, but without limitation, the stopper 28 can be made of rubber orsteel. These materials, however, are less preferable because rubberdeforms under pressure, and steel, under high-pressure operatingconditions, can crack the cap 28 when the stopper 28 seats against thevalve seat due to its high density of steel.

FIG. 8 illustrates the stopper 28 within the assembled valve 10. Thestopper 28 is placed in the fitting 20 within the cavity 40, and isretained by the post 44, the extension 50, the vanes 48 and the valveseat 58. The gasket 70 is placed within the cap 30 against the lowerface 68 of the annular ridge 60, and the cap 30 is threaded over theupper end 32 of the fitting 26.

The stopper 28 can be arranged within the valve 10 to operate at avariety of locations within the valve housing, however. For instance,the stopper can operate within a space defined between the primary andbranch passages (as illustrated in FIG. 6, for example) or can operateentirely within the primary passage (as would be the case if the valveseat were positioned at the intersection between the primary passage andthe branch passage). The illustrated arrangement of stopper and valveseat within the valve housing therefore is merely exemplary.

The valve's passages and ports can of course be configured in a varietyof sizes and shapes in order to suit various sized and shaped pipes withwhich the valve is used. An exemplary one-inch fitting is providedbelow.

In the exemplary embodiment, the branch passage 38 has an inner diameterof 1.0 inch (2.54 cm) and the valve throat 64 has a diameter of 0.625inch (1.59 cm). The stopper 28 desirably has a diameter of about 0.75inch (1.91 cm). Other exemplary dimensions for the one-inch fluid flowcontrol valve 10 include inner diameters of 1.0 inch (2.54 cm) for theprimary passage 34, the branch passage 38, and the hemispherical recess42 (i.e., the recess has a radius of 0.5 inch (1.27 cm)).

The extension 50 extends a height of 0.34 inch (0.86 cm) from the floor46 of the primary passage 34, leaving 0.66 inch (1.68 cm) clear, whichis insufficient for the stopper 28 (0.75 inch) to escape. A length (inthe direction of the primary axis P_(A)) and a width of 0.15 inch (0.38cm) provides sufficient strength to allow the extension 50 to performits intended function. The vanes 48 extend vertically across the primarypassage 38, and are symmetrically spaced about 0.2 inch (0.51 cm) toeither side of a vertical center-plane that bisects the primary passage34. The vanes 48 in this position lie 0.4 inch (1.02 cm) apart from eachother. The vanes desirably have a thickness of about 0.1 inch (0.25 cm)and a length along the primary passage 34 of about 0.5 inch (1.27 cm).Such dimensions and arrangement within the primary passage 34 aid inpreventing the stopper 28 from escaping through the second effluent port24, while providing a flow straightening effect to the flow downstreamof the recess 42 and consequently increasing the head downstream of thevalve 10.

The post 44 in the illustrated embodiment extends upwardly to a heightof about 0.66 inch (1.68 cm) from the floor of the recess 42, andterminates approximately 0.19 inch (0.48 cm) below the bottom surface 46of the primary passage 34. When the stopper 28 rests on the post 44 (seeFIG. 6), it extends just over half way into the primary passage 34,leaving a clearance of about 0.45 inch (1.14 cm) between the stopper 28and the intersection between the primary passage 34 and the branchpassage 38.

It will be understood that the above-noted dimensions are merelyexemplary. The dimensions each depend upon one another, upon the densityand shape of the stopper, the desired normal flow conditions, and thepredetermined flow rate through the branch passage at which the valve isto close. It is understood that one of skill in the art can readily varythe dimensions to adapt the valve for a particular application throughroutine experimentation, in view of the disclosure herein.

The operation of the control valve 10 will now be described in detail.

With reference again to FIG. 8, the control valve 10 is illustrated incross-section during normal flow conditions with the stopper 28 in afirst position. The valve 10 is arranged within the irrigation systemsuch that water flows through the primary passage 34 from the influentport 20 to the second effluent port 24. The straightening vanes 48 arepositioned downstream of the branch passage 38 and the extension 50 isarranged upstream of the branch passage 38.

Water flows from the upstream irrigation pipe 12 into the influent port20 and primary passage 34 of the valve 10, as schematically indicated bythe in-flowing arrow 76 shown in FIG. 8. A portion of this water flow(schematically illustrated by arrows 78) flows through the primarypassage 34 past the branch passage 38, through the downstream side ofthe primary passage 34, and out the second effluent port 24 into thedownstream irrigation pipe 14 for delivery to a subsequent valve orfitting. The balance of the water flow through the valve 10, asschematically illustrated by flow directional arrows 80, flows upwardlyinto the branch passage 38 to the first effluent port 22 and thence tothe riser 16 (shown in phantom).

As illustrated in FIG. 8, water flowing into the branch passage 38 isrelatively unrestricted by the extension 50, which is situated on theopposite side of the primary passage 34 from the branch passage 38. Theflow split created by the intersection between the passages 34, 38 tendsto create turbulence, which has an adverse effect on the head downstreamof the second effluent port 24. The straightening vanes 48, however,tend to smooth the turbulence within the water flow downstream of theintersection to improve head downstream of the valve 10.

During normal operation, water flow through the branch passage 38 intothe riser 16 is restricted by the sprinkler head 17. Accordingly, therate of flow through the branch passage 38 is relatively low. Forexample, flow rate through a typical sprinkler head is between about 5gallons/minute (18.9 liters/minute) and 25 gallons/minute (94.6liters/minute).

A portion of the water passing through the cavity 40 flows over theupper surface of the stopper 28 closest to the branch passage 38; i.e.,over the surface area of the spherical stopper 28 above the stopper'smidsection. Under normal flow conditions, at least some water also flowsover the opposite surface, furthest from the branch passage 38 (belowthe stopper 28 for the illustrated orientation). The post 44 spaces thestopper 28 from the surface of the recess 42 so as to allow flow belowthe stopper 28. Water below the stopper 28 flows around the extension 50and the post 44, which present minimal resistance to flow whilemaintaining the stopper 28 in the desired position. The stopper 28 inthis position is desirably offset downward from the central flow axisP_(A) of the primary passage 34. In an exemplary embodiment, the stopper28 normally lies about no more than 1.5 inches (3.81 cm) from thecentral axis. The stopper 28 advantageously is arranged relative to therecess 42 such that most of the water passing through the primarypassage 34 flows over the stopper while a significant portion flowsbeneath the stopper 28. Thus, under normal flow conditions, water flowsboth under the stopper 28 and over the stopper 28.

Several forces act upon the stopper 28 when positioned within the waterflow through the cavity 40. In particular, different flow rates aboveand below the stopper 28 cause a pressure differential which exerts aforce upon the stopper 28. Flow characteristics within the recess 42(e.g., eddies) also vary the pressure below the stopper 28. Gravityexerts a downward force upon the stopper 22, the magnitude of whichdepends upon the dimensions and density of the stopper 28. And buoyancycaused by the displacement of water exerts some degree of upward forceupon the stopper 28, depending upon the dimensions or volume of thestopper 28. All of these forces influence the movement of thefree-floating stopper 28, at least to some degree, within the cavity 40.

Under normal flow conditions, the forces desirably result in an overalldownward force to bias the stopper 28 toward the post 44 and to preventthe stopper 28 from rising into the branch passage 38. As the flow ratesare all determined by the chosen dimensions for the passages 34, 38,etc. of the valve 10, the density of the stopper 28 must be chosen suchthat the force of gravity at least balances against the other forces andthe stopper 28 does not rise to or chatter against the valve seat 58during normal flow. Additionally, minor fluctuations in flow rate suchas may be expected during normal flow also can be overcome by the forceof gravity to prevent premature closure of the valve 10 or chattering ofthe valve stopper 28.

A stopper made of too dense a material, however, can remain stationary(i.e., seated on the post 44) even during abnormal flow conditionswithin a low-pressure system, or the stopper can damage to the interiorstructures of the fitting 26. A glass stopper, as noted above, providesa sufficient weight to properly function within systems having linepressures ranging between 5 psi (34.5×10³ Pa) and 90 psi (620.6×10³ Pa).

Where the rate of flow above the stopper 28 exceeds that below thestopper 28, a low pressure zone is created above the stopper 28, whichtends to create an upward force acting upon the stopper 28. Any suchupward force during normal flow conditions is overcompensated by theforce of gravity upon the stopper 28, such that the stopper 28 tends toremain within the cavity 40 below the valve seat 58. As flow below thestopper 28 tends to counter upward forces on the stopper 28 created bythe flow above the stopper 28, any amount of flow below the stopper 28is advantageous in preventing the stopper 28 from prematurely rising toblock the branch passage 38 during normal flow conditions. Desirably,however, during normal operation the rate of water flow above thestopper 28 does not substantially exceed the rate of flow below thestopper 28, to ensure a stronger tendency for the stopper 28 to remainwithin the primary passage 34 and seated above the post 44.

With reference to FIG. 9, abnormal flow conditions are shown where therate of flow through the branch passage 38 exceeds a predetermined rate.The predetermined rate is chosen to be between the rate of flow duringnormal operation, and the rate of flow under a fault condition. Thecontrol valve 10 is illustrated in FIG. 9 shortly after the riser 16 hasbeen broken, such that the sprinkler head 18 no longer restricts waterflow through the riser 16. As illustrated, a large stream of water 82initially rushes through the branch passage 38 and out the broken riser16. For example, water flow through a broken riser in an irrigationsystem normally of a head of 40 psi (275.8×10³ Pa) to 60 psi (413.7×10³Pa), with a diameter of 1.0 inch (2.54 cm), typically ranges betweenabout 20 gallons/minute and 60 gallons/minute. The dimensions andmaterials are thereby chosen to close the valve 10 when water flowthrough the branch passage 38 exceeds about 10 gallons/minute, a ratebetween that of normal operation and that of the broken riser 16.

The increased stream of water through the branch passage 38 after theriser 16 has been broken facilitates in moving the stopper 28 toward thevalve seat 58. One or more of the following factors may contribute to oraccount for the stopper's movement toward the valve seat 58. As notedabove, water flows both above and below the stopper 28 under normal flowconditions (FIG. 8). The stopper 28 is thus already positioned withinthe water flow under normal flow conditions. During abnormal flowconditions, such as created by the broken riser 16 shown in FIG. 9, therate of water flow above the stopper 28 (schematically represented byflow directional arrows 80 a in FIG. 9) increases when the riser 16breaks, relative to the rate of flow under the stopper 28 (schematicallyillustrated by flow directional arrows 78 a). The increased rate offluid flow above the stopper 28 creates a fluid pressure differentialabove and below the stopper 28. The relatively higher fluid pressure inthe fluid below the stopper 28 exerts an upward force on the stopper 22.The size and density of the stopper 28, the dimensions of the fitting 26and cap 30, and the relative position of the stopper 28 within the fluidflow are all chosen such that the upward force is sufficiently strong toovercome the countering force of gravity, thereby lifting the stopper28, only under the selected abnormal flow conditions. Friction, momentumand/or drag on the stopper 28 may also contribute to the stopper'smovement toward the valve seat 58.

The straightening vanes 48 prevent the stopper 28 from travelling outthrough the second effluent port 24 as the stopper 24 rises.

With reference to FIG. 10, the control valve 10 is shown in the closedposition under abnormal flow conditions, with the stopper 28 in a secondposition. Once flow through the branch passage 38 exceed thepredetermined rate, the stopper 28 rises until it is entrained withinthe flow through the branch passage 38. The flow carries the stopper 28and forces it to seat against the valve seat 58 of the cap 30. Moreparticularly, the stopper 28 seats directly against a portion of thegasket 70 which projects below the facet 66 of the valve seat 58. Thestopper 28 engages with the gasket 70 to at least substantially closeoff water flow to the riser 16. The stopper 28 tends to contact thegasket 70 about a section just below the edge intersection 72 on theannular ridge 60.

The deformable gasket 70 serves to both cushion impact from the stopper28, preventing cracking or other damage to the cap 30, as well as to aidin substantially sealing the first effluent port 22. Water continues toflow through the primary passage 34, allowing water to continue to flowunobstructed to unbroken risers within the irrigation system, whilefluid pressure within the branch passage 38 maintains the stopper 28 inits closed position, seated against the valve seat 58.

The movement of the stopper 28 between the first position (FIG. 8),under normal flow conditions, and the second position (FIG. 10), underabnormal flow conditions, defines a stopper axis which extends throughopposite sides of the stopper 28. Note that, in the first position,water flows over both opposite sides (e.g., the upper and lower sides ofthe stopper 28). When abnormal flow conditions arise, the stopper 28reliably rises to the valve seat 58 and inhibits fluid flow through thebranch passage 38.

A telltale stream of fluid 84 desirably is allowed to bypass the stopper28 while the stopper 28 is seated against the valve seat 58. In theillustrated embodiment, fluid escapes through the notches 74 of thegasket 70 which function as telltale ports in the illustratedembodiment. As the notches 74 are aligned with the facet 66 and extendoutwardly beyond the intersection edge 72, the notches 74 form openingsbetween the stopper 28 and the valve seat 58 to allow a small amount ofwater flow around the stopper 28, through the valve throat 64 and upthrough the broken riser 16.

Due to fluid pressure within the branch passage 38 and the small size ofthe telltale ports 74, a small volume of water escapes with highvelocity, such that the telltale stream 84 produces a thin fountain ofwater that reaches considerable height. The telltale stream 84 is smallenough to prevent flooding or erosion, yet large enough to serve as avisible indication that the flow control valve 10 has been tripped(i.e., closed). Other than the telltale stream 84, the first effluentport 22 remains substantially sealed under abnormal flow conditions.“Substantially sealed,” refers to a condition in which the telltalestream 84, along with any other leakage at the first effluent port 22,flows at a rate less than about 30% of a restricted flow through thebroken riser (such as represented by the large stream 82 of FIG. 9). Thetelltale stream 84 should flow at less than about 10% of a restrictedflow, desirably between about 0.1% and 5%, and particularly betweenabout 1% and 3% of a restricted flow. The telltale stream 84 may thusalert an irrigation technician to the existence of a broken riser, andthe riser may be replaced or repaired.

The illustrated control valve 10 thus serves to arrest fluid flowthrough a branch passage 38 under abnormal flow conditions. Under normalflow conditions, fluid flows both above and below the stopper 28,minimizing the risk of over-sensitivity of the valve 10 to minor flowrate fluctuations, as well as improving the reliability of the valvewhen used in systems operating under various head (e.g., 5 psi (34.5×10³Pa) to 90 psi (620.6×10³ Pa)).

Having described the above-noted aspects, features and advantages in thecontext of a preferred embodiment, it will be understood that manymodifications and variations thereto are possible, all of which fallwithin the true spirit and scope of the invention. Thus, broadlyspeaking, the present fluid flow control valve comprises a housing thatdefines at least first and second conduits. The first and secondconduits intersect within the housing. A seat is located at leastpartially within the second conduit, and a moving stopper selectivelycooperates with the seat to at least substantially close the secondconduit. The stopper is movable between a first position, where thestopper lies at least partially within the first conduit, and a secondposition where the stopper seats against the seat. The movement of thestopper between the first and second positions defines an axis whichextends through opposite sides of the stopper. The stopper is arrangedwithin the first conduit when in the first position such that fluidflows over opposite sides of the stopper.

Another aspect of the invention, which is apparent from theabove-description, is a fluid flow control device that comprises aninfluent port which opens into a cavity. At least one effluent port alsocommunicates with the cavity. A stopper seat is positioned between theeffluent port and the cavity. A stopper operates within the cavity toselectively engage the seat and substantially seal the effluent port. Atelltale port communicates with the cavity such that some fluid flowsfrom the cavity through the telltale port with the plug seated againstthe plug seat.

An additional aspect of the invention involves an irrigation valve foruse with a riser of an irrigation system. The valve includes a primarypassage extending from a first end of the valve. The first end isintended to receive a portion of an irrigation pipe of the irrigationsystem. A branch passage extends normal to the primary passage in anupward direction and communicates with the primary passage. The branchpassage terminates near an upper receptacle of the valve. The receptacleis intended to receive an end of the riser. A recess is formed on a sideof the primary passage opposite the branch passage, with a supportprojecting from the recess toward the branch passage. A valve seat islocated between the upper receptacle and the primary passage, and amovable stopper is located within the primary passage below the valveseat. The support is arranged to maintain the stopper within awater-flow stream through the primary passage and the recess undernormal flow conditions. The stopper is movable relative to the primarypassage under abnormal flow conditions to a position in which thestopper seats against the valve seat to inhibit water flow through thebranch passage.

The present fluid flow control device can also be described as having aprimary passage communicating with the secondary passage. A valve seatcommunicates with the secondary passage, and a movable stopperselectively cooperates with the valve seat to inhibit fluid flow throughthe secondary passage. At least one vane is positioned downstream of anintersection between the primary and secondary passages. The vaneextends across the primary passage and is arranged parallel to adirection of fluid flow through the primary passage. The vane also isconfigured to provide a flow straightening effect within the fluidpassing through the primary passage downstream of the intersection.

FIGS. 11-13 disclose another embodiment of the present fluid flowcontrol valve which includes additional aspects, features and advantagesof the invention. In general terms, the control valve includes a housingthat defines a first passage extending from a first end. The first enddefines an influent port and is intended to receive a portion of aninlet pipe. A second passage extends from and communicates with thefirst passage. The second passage terminates near a receptacle which isadapted to receive an end of an outlet pipe. A valve seat is locatedbetween the receptacle and the first passage. A biasing device ispositioned between the valve seat and the influent port and biases amovable stopper which is located within the housing near the valve seat.At least a portion of the biasing device is movable within the housingto permit the stopper to seat against the valve seat under abnormal flowconditions.

With reference now to the specific embodiment illustrated in FIGS.11-13, a fluid flow control valve 90 has a similar configuration to thevalve illustrated in FIGS. 1-10, except for the inclusion of a biasingdevice 94 and possibly the construction of a stopper 92. The stopper 92,while desirably spherical like the stopper 28 described above, can havedifferent characteristics from the stopper 28 of the previouslydiscussed embodiment, for reasons which will be apparent from thediscussion below. The balance of the valve 90, however, is structured inaccordance with the above description. Similar features thus areascribed the same reference numerals used for corresponding elementsfrom the embodiment of FIGS. 1-10 for ease of description.

The biasing device 94 is provided for maintaining the position of thestopper 92 within the fluid flow path under normal flow conditions. Inthe illustrated embodiment, the biasing device takes the form of aspring retainer comprises of a material which exhibits a degree offlexibility, such as, for example, but without limitation,polyvinylchloride (“PVC”).

The illustrated biasing device 94 includes an annular rim 95 whichcircumscribes a cylindrical wall 96 of the device 94. The outer surfaceof the wall 96 is desirably sized and shaped to slip fit into the branchpassage 38, while the inner surface of the cylindrical wall 96 has adiameter larger than that of the stopper 92. At least one deflectablefinger 97 depends from the wall 96, and desirably three or more fingers97 depend from the wall 96.

The fingers 97 are each angled inwardly at an elbow 98, such that alower segment 99 projects inwardly from the wall 96 into the cavity 40.This angled configuration is desirably achieved by integrally moldingthe entire finger 97 in the angled configuration. It will be understoodthat the angled configuration may be also be achieved by stamping andbending a part, or by gluing or welding finger segments together.

Desirably, the fingers 97 are deflectable with a resilient tendency toreturn to the illustrated shape. The illustrated fingers 97 thus serveas cantilever springs. It will be understood from the description belowof the biasing device function that the biasing device may take otherforms, such as, for example, a helical spring, in other arrangements.

In the illustrated embodiment, the biasing device 94 includes threedepending fingers 97 which are spaced around the circumference of thewall 96 at 120° from one another. Desirably, each segment 99 terminatesat a relatively smooth end 100. The ends 100 define an opening too smallto allow the stopper 92 to pass upwardly toward the valve seat 58 duringnormal operation.

With reference to FIGS. 12 and 13, the valve 90 is shown assembled withthe biasing device 94 secured therein. The biasing device 94 is insertedinto the branch passage 38 of the fitting 26. The annular rim 95 sitsatop the upper end of the fitting 26 to prevent the biasing device 94from slipping further into the valve cavity 40. In the illustratedembodiment, the gasket 70 is fitted within the cap 30 to engage thelower face 68 of the ridge 60. The cap 30 is then threaded onto thefitting 26, such that the gasket 70 is retained against with the rim 95of the biasing device 94. The rim 95 and the gasket 70 are therebysecured between the cap 30 and the fitting 26, as illustrated.

FIG. 12 illustrates the valve and the stopper under normal flowconditions. The biasing device 94 engages the stopper 92 and preventsthe stopper 92 from rising to the valve seat 58. In particular, the ends100 of the inwardly bent segments 99 can engage the spherical surface ofthe illustrated stopper 92.

It will be understood by one of skill in the art, therefore, that thestopper 92 may be less dense than the stopper 28 of the firstembodiment, since the biasing device 94 aids gravity in preventing thestopper 92 from rising under normal flow conditions. In the illustratedembodiment, the stopper 92 is insufficiently dense to rest upon the post44 under normal flow conditions, and is instead buoyed to engage thebiasing device 94. The arrangement of the extension 50, thestraightening vanes 48 and the walls of the fitting 26 about the cavity40 ensure that the opening defined by the ends 100 of the fingers 97provides the only stable position for the stopper 92 under normal flowconditions (both transient and steady-state). The arrangement of thesecomponents cause the stopper 92 to generally center between the threefingers of the biasing device 94. The upward forces acting on thestopper 92 under normal flow conditions are insufficient to overcome thespring force of the biasing device and force the fingers 97 open.Accordingly, the illustrated biasing device 94 serves to support thebuoyant stopper 92 within the water flow, without allowing the stopper92 to rise to the valve seat 58.

Thus, as illustrated by the embodiment discussed below, the post 44 maybe unnecessary to keep the stopper 92 within the midst of the waterflow. In other arrangements, however, the stopper 92 may be more denseand the post 44 would serve to support the stopper 92 under normal flowconditions. The post 44 also functions to initially support the stopperwhen flow begins through the fitting 26.

FIG. 13 illustrates the valve 90 under abnormal flow conditions, such asthose created by a broken riser (see FIGS. 9 and 10) or other faultcondition. As discussed above, the low pressure created above thestopper 92 by the surge of fluid through the branch passage 38,increases the upward force exerted upon the stopper 92. This upwardforce upon the stopper 92 is translated into an outward force upon thesegments 99 through interaction of the stopper surface with the fingerends 100. Desirably, the surface of the stopper 92 is spherical, thoughother configurations may also accomplish the desired translation ofupward force to outward force.

The geometry and material of the illustrated depending fingers 97 arechosen such as to permit outward deflection of the fingers 97, such asat the illustrated crease 98, under the force created by the abnormalflow conditions. The stopper 92 is thus permitted to rise to the valveseat 58 and maintained there by water pressure, substantially sealingthe effluent port 22.

Desirably, the gasket 70 of this embodiment also includes telltale ports74 to allow remote detection of a closed valve 90. While illustrated inconjunction with the extension tab 50 and vanes 48, the valve 90 mayutilize other arrangements to prevent the stopper 92 from escapingthrough the influent or effluent ports 20, 24. The recess 42 and post 44desirably ensure maintenance of the stopper 92 within the normal flowpath of fluid.

In contrast to the embodiment of FIGS. 1-10, the valve 90 does notdepend upon gravity to prevent the stopper 92 from prematurely shuttingdown water flow. Selection of a highly buoyant stopper 92 may becompensated by selection of a high spring constant for the particularbiasing device 94 to prevent premature valve tripping, as will beunderstood by one of skill in this art in light of the disclosureherein.

FIGS. 14-19 illustrate a fluid flow control valve 120 in accordance withanother preferred embodiment of the present invention. For ease ofdescription, similar features are ascribed the same reference numeralused for corresponding elements from the embodiments of FIGS. 1-13.

The valve 120 comprises a valve cap or housing 122, a keeper or rod 124,a stopper 126 and a cage or basket 128. The top portion 130 of thebasket is press fit or otherwise secured (e.g. by epoxy, ultrasonicwelding, etc.) within the lower receptacle 134 of the valve cap 122. Thebottom portion 132 of the basket supports the stopper 126 generallyabove the horizontal fluid flow within the fitting 140. The stopper 126is further held in place by the rod 124 or biasing device, which ispositioned within the riser 16 above the stopper 126, which acts as abiasing device. Thus, the stopper 126 is generally contained within theflow. During normal steady-state flow, the location of the stopper 126does not significantly change, and thus movement by the stopper does notsignificantly contribute to vibration within the system.

Advantageously, the valve 120 can be integrated into any of a variety oftypes of junctures. In the embodiment illustrated in FIGS. 14 and 15,the fitting 140 does not include a recess on the opposite side of thebranch passage, as in the embodiment illustrated in FIG. 1. In thismanner, the valve 120 can be used, for example, with a pre-existingT-junction, elbow junction or comer junction in an irrigation system.

The individual components of the valve 120 will now be described indetail. The valve 120 will be described in terms of the illustratedarrangement within the irrigation system with a water flow in ahorizontal direction between an influent port 121 and the secondeffluent port 125, and a water flow in the vertical direction throughthe first effluent port 123. It should be noted that the valve 120 ofthis embodiment is bidirectional and, thus, the labels of “influent” and“effluent” are merely exemplary terms used to aid in the description ofthe valve. Also, the terms “horizontal” and “vertical,” of course,depend on the chosen orientation of the valve 120 and are used here tosimplify the description. Likewise, terms of orientation, such as“above”, “below”, “upper” and “lower”, are used in the context of theillustrated embodiment; however, because other orientations arepossible, the present invention should not be limited to the illustratedorientation. Thus, terms of orientation, such as “horizontal”,“vertical”, “above”, “below”, “upper”, “lower”, etc., are used hereinsolely for purposes of illustration as those skilled in the art willappreciate that the valve of the present embodiment, as well as thosedescribed below, are not orientation-sensitive, and that otherorientations of the valve 120 are possible.

The valve cap 122, which is positioned between the riser 16 and thefitting 140, has an inner and an outer surface. As best seen in FIG. 15,the outer surface of the valve cap 122 defines a first portion 139 sizedto cooperate with the internal threads of the upper end of the fitting140, and a second portion 141 having a larger outer diameter than theouter diameter of the first portion 139. In the illustrated embodiment,the first portion 139 is externally threaded.

FIG. 16a is a perspective, cross-sectional view of the valve cap 122shown in an upside-down position relative to the valve cap 122 shown inFIGS. 14 and 15. The inner surface of the valve cap 122 defines a firstor lower receptacle 134, a second or upper receptacle 136, and a valveseat 138 between the first and second receptacles 134, 136. An innershoulder 135 is formed on the inner surface of the valve cap 122 withinthe first receptacle 134. Otherwise, the diameter of the firstreceptacle or cavity 134 is generally constant. The inner shoulder 135is formed by a counterbore of the valve cap 122 which receives the topportion 130 of the basket 128.

The inner surface 137 of the upper receptacle 136 near the valve seat138 is sloped so that the diameter of the upper receptacle 136 issmallest near the valve seat 138 and increases toward the upper end ofthe receptacle 136. This sloped inner surface of the upper receptacle136 generally has a funnel-like shape which aids in positioning the rod124 within the housing as described below.

In the illustrated embodiment, an upper portion 139 of the secondreceptacle 136 is internally threaded. The threads are sized to engagethe external threads of a corresponding riser 16.

Similar to the valve seat 58 shown in FIG. 7, the valve seat 138comprises a generally annular ridge 142 interposed between the upperreceptacle 136 and the lower receptacle 134 of the valve cap 122. Theridge 142 has an annular inner face which defines a valve throat 144between the upper and lower receptacles 134, 136.

In a preferred embodiment, the valve seat 138 lies within the firstportion 141 of the valve cap 122 at a point spaced from the juncturebetween the first portion 141 and a second portion 143. Thus, when thevalve cap 122 and the fitting 140 are coupled together, the valve seat138 is positioned within the fitting 140, as shown in FIG. 14.Advantageously, because the valve seat and stopper are within thefitting 140, the valve will continue to function even if the valve cap122 is severed between the first portion 141 and the second portion 143.

As best seen in FIG. 16a, the valve seat 138 can include one or moreslots or notches 146 formed along the inner portion of the ridge 142.The notches 146 form a plurality of telltale ports, similar to thetelltale ports described above, which allow remote detection of a closedvalve when the riser 16 has been broken. The cross-sectional flow areasof the telltale port is smaller than the cross-sectional flow areathrough the throat 144 of the valve seat 138. In the illustratedembodiment, a plurality of notches 146 are evenly spaced about the innerperiphery of the ridge 142. In other embodiments, the valve seat 138 mayinclude only one notch or may include a plurality of notches spaced atirregular intervals about the inner periphery of the ridge 142.

The ridge 142 further comprises a chamfer or facet 148 on the inlet sideof the valve throat 144. The chamfer 148 forms a beveled transitionbetween an inner face 150 and a lower face 152 of the ridge 142.

In a preferred embodiment, the valve cap 122 also includes one or moreprotrusions 145 (FIG. 16) projecting from the valve cap edge. Theseprotrusions 145 cooperate with a shoulder within the fitting 140. Whenthe valve 122 is attached to the fitting 140, the protrusions 145depress against an inner surface rim or shoulder of the fitting, therebycreating dimples in the inner surface rim at the protrusion locations.Thus, the protrusions 145 facilitate a tight connection between thevalve cap 122 and the fitting 140. This connection prevents the valvecap 122 from unintentionally separating from the fitting 140 when pipes,risers or other fixtures are removed or adjusted.

With reference to FIG. 14, the stopper 126 is positioned below the valveseat 138. Under normal flow conditions, the stopper 126 is positioned adistance away from the valve seat 138. As discussed above, the stopper126 in the illustrated embodiment is a free-floating spherically-shapedball. Similar to the embodiment shown in FIGS. 11-13, the stopper 126may be less dense than the stopper 28 of the embodiment shown in FIGS.1-10 because the rod 124 aids gravity in preventing the stopper 126 fromrising under normal flow conditions including both normal steady-stateand transient conditions. For example, in one mode, the specific gravityof the stopper 126 is less than 1.0.

During normal fluid flow, the stopper 126 is supported by the basket128. As best seen in FIG. 16b, the basket 128 includes an upper portion130 and a lower portion 132. The upper portion 130 of the basket 128 isconfigured to cooperate with and is coupled to the first portion 139 ofthe valve cap 122. In the illustrated embodiment, the upper basketportion 130 is press fit against the inner surface of the valve cap 122within the lower receptacle 134 of the valve cap. In other embodiments,the upper portion 130 may be held in place by other means, including,but not limited to, ultrasonic welding, adhesives, bonding, friction,threaded engagement, and other known methods of affixation.

In the illustrated embodiment, the upper portion 130 of the basket hasan annular shape with an inner and an outer diameter. The outer diameterof the upper portion 130 can be slightly greater than the diameter ofthe first receptacle 134 of the valve cap 122 so that the upper basketportion 130 can be held by a press fit within the counterbore of thevalve cap 122, against the shoulder 135. In other embodiments, thebasket 130 can be affixed to the valve cap 122 by other means (such asbonding, friction, ultrasonic welding, etc.), and thus it the outerdiameter of the upper basket portion 130 does not have to the largerthan the diameter of the first receptacle 134.

The inner diameter of the upper portion 130 of the basket is desirablythe same as the diameter of the first receptacle above the shoulder 135.Therefore, when the upper portion 130 of the basket 128 is positionedwithin the first receptacle 134, there are no appreciable ridges orshoulders between the inner surfaces of the upper portion 130 of thebasket and of the first receptacle 134.

In the illustrated embodiment, the upper portion 130 and the lowerportion 132 of the basket are integrally formed. The lower portion 132of the basket 128 includes a bottom support 147 and a plurality of arms145 between the bottom support 147 and the upper portion 130 of thebasket. The arms 145 suspend the bottom support 147 at location spacedapart from the upper portion 130. Between the arms 145 are openings 149which permit fluid to flow within the basket 128.

In the illustrated embodiment, the bottom support 147 of the basket hasa bowl-like shape to generally match the contour of the stopper 126. Thebottom support 147 desirably includes a small opening 133 through whichfluid can flow. The opening 133 is smaller in size than the stopper 126so that the stopper cannot pass through the opening 133. For instance,in one embodiment, the diameter of the opening 133 is approximately0.125 inch (0.31 cm). The opening 133 allows fluid to flow within thebasket 128 around the stopper 126. Fluid flow through the basket 128serves to spin or flush the stopper 126 to prevent build up under thestopper 126 of sediment and debris from the sprinkler system.

In other embodiments, the basket 132 may be configured to provide forfluid flow within the basket in other ways, such as by a post (notshown) extending in the vertical direction from the bottom of thebasket. Such a post could be similar to the post 44 shown in FIGS. 2-6,and would support the stopper 126 within the basket.

As best seen in FIG. 14, the lower portion 132 of the basket 128 andmost of the stopper 126 are positioned within the primary passage 34during normal flow conditions (FIG. 14). Placement of the basket 128within the primary passage 34 minimizes head loss to the sprinkler 162by acting to divert a portion of the main flow through the basketopenings 149.

FIG. 20 depicts a graph illustrating the amount of head loss versus flowrate through a flow control valve configured in accordance with theembodiment shown in FIG. 14. This data was obtained empirically using aflow control valve with a 12 inch (30.48 cm) riser having a width of0.75 inch (1.91 cm). At a fluid pressure of 40 psi (275.8×10³ Pa), thehead loss through the valve was determined at various flow rates between1 gallon/minute (gpm) (3.8 liters/minute) and 8 gpm (30.3liters/minute). As illustrated in FIG. 20, for flow rates between 1 gpm(3.8 liters/minute) and 6 gpm (22.7 liters/minute), the head lossthrough the valve was less than 2.0 psi (13.8×10³ Pa). The head loss ofthe described flow control valve is thus almost negligible, in that ahead loss of less than 5 psi (34.5×10³ Pa) is generally acceptablewithin the industry for flow rates of 1 gpm (3.8 liters/minute) and 8gpm (30.3 liters/minute).

With reference to FIGS. 14, 17 and 18 a-b, the rod 124 is principallypositioned within the riser 16 directly above the stopper 126. The rod124 includes a disc-shaped foot 125 at the lower end of the rod 124. Thefoot 125 is positioned generally normal to the longitudinal axis of therod 124 and has a diameter less than the diameter of the valve throat144. During normal fluid flow, the disc foot 125 of the rod 124 isgenerally in contact with the stopper 126 to prevent the stopper 126from prematurely seating against the valve seat 138. A portion of therod 124 extends through the valve cap 122, including the valve throat144 and the upper and lower receptacles 134, 136.

The rod 124 desirably can be sized to fit within risers of varyinglengths or within an assembled length of risers. While the initiallength of the rod 124 may vary, the length of the rod 124 can also beeasily sized to fit within a shorter-length riser 16. As illustrated inFIGS. 17 and 18b, the rod 124 desirably has one or more grooves 154spaced apart longitudinally along the rod 124. The grooves 154 dividethe rod 124 into one or more sections. In one mode, each groove 154 is0.004 inch (1 mm) wide and 0.004 inch (1 mm) deep.

By applying a shearing stress to one of the grooves 154 on the rod, theextra length portion of the rod 124 can be easily snapped off to shortenthe rod 124 to the desired length. For example, a 12 inch (30.5 cm) rodcan be easily sized to fit within an 8 inch (20.32 cm) riser bymeasuring an 8 inch section of the rod and applying pressure to thenearest groove which would allow an approximately 4 inch (10.16 cm)section of the rod to be broken off, resulting in a rod equal to orslightly larger than the desired length.

On the other hand, if the riser 16 is greater 12 inches, one or morerods 124 may be stacked longitudinally to fit with a riser 16 or riserassembly. The rods may also be coupled or linked together within theriser or riser assembly, such as by a sleeve or other suitable couplingmechanism.

As best illustrated in FIG. 18b, which shows a cross-sectional view ofthe rod 124 taken along line 18 b—18 b of FIG. 17, the rod in theillustrated embodiment has a cross-sectional shape like a plus signsymbol (+). Other cross-sectional shapes of the rod are also possible,such as, but not limited to, circular.

The size of the rod cross-section is smaller than the inner diameter ofthe riser or fluid delivery section to permit the rod to fit within theriser 16. Desirably, the cross-sectional size of the rod is sufficientlysmall relative to the inner diameter of the riser so that fluid can floweasily over the rod 124 through the riser 16.

The rod 124 desirably further includes a compression spring 156 and aplurality of fins 158 that extend outward from the center of the rod. Inone mode, the rod 124 is a single molded piece, including the spring 156and fins 158. In other modes, however, the rod 124 may comprise multiplepieces fused, welded or interconnected together.

In the illustrated embodiment, the spring 156 is located on the lowerportion of the rod 124. The spring 156 compensates for manufacturingtolerances of the length of the rod 124 and for tolerance stack-upwithin the sprinkler head-riser-valve assembly. For instance, whenattaching the sprinkler head to the riser, the sprinkler head may bescrewed onto the riser using all or only a portion of the sprinkler orriser threads. In addition, when stacking a plurality of rods 124 withina riser assembly, any inaccuracies in the length of the rods or in theassembly are compounded. The spring 156 can be compressed, if necessary,to absorb tolerance stack-up within the assembly. In this manner, thelength of the rod 124 can be varied to compensate for inaccuracies inthe effective length between the bottom of the sprinkler head and thestopper.

A plurality of fins 158 extend from the rod 124 at various locationsalong the length of the rod 124, except at the location of the spring156. In one embodiment, each fin 158 is semi-circular in shape; however,the fins 158 may be shaped in other ways as well (e.g. rectangular). Inaddition, the fins 158 provide a flow straightening effect through theriser 16. The fins 158 desirably present a thin profile to the fluidflow, but have a sufficient length to straighten, at least to somedegree, the fluid flow past the fins.

In the illustrated embodiment, four fins 158, which are generally normalto each other, extend from one location of the rod 124. The fins 158extend from the outwardly extending sections of the rod 124. Additionalfins 158 extend from the rod 124 at other locations.

Desirably, the fins 158 are sized to position the rod 124 generallywithin the center of the riser 16. In the illustrated embodiment, thewidth of the rod 124 and two fins 158 extending from opposite sides ofthe rod 124 is only slightly smaller than the inner diameter of theriser 16. In addition, by centering the rod 124 within the riser, thefins contribute to the stackability of one or more rods 124 within theriser 16. For example, if the riser 16 or a combination of risers 16have an overall length greater than the length of one rod, additionalrods can be easily stacked atop the first rod as necessary by simplydropping the rods into the riser one after another. The fins 158 thusallow for easy and convenient assembly of the rods within the risers ofvarying lengths.

In addition, as best seen in FIG. 14, the set of fins 158, which islocated below the spring 156, assists in centering the rod 124 and thefoot 125 relative to the valve throat 144 so that the rod 124 and discfoot 125 are positioned above the stopper 126. The sloped inner surface137 of the upper cavity 136 directs the fins 158 to assume a centralposition within the upper cavity 136 so that the rod 124 is generallycentered through the valve throat 144. As a result, the disc foot 125 isalso positioned above the stopper 126 and centered below the valvethroat 144.

With reference to FIG. 17, a cap 160 at the top of the rod 124interfaces with the lower surface of the sprinkler and allows for fluidflow through the riser to the sprinkler head. The cap 160 is shaped tofit over the top end of the rod 124. Thus, in the illustratedembodiment, the cap 160 has a bottom portion 161 which is shaped to mateover the +symbol shape of the rod 124. This bottom portion 161 fits overthe top end of the rod 124 after the rod 124 has been sized to fitwithin the riser 16. When the cap 160 is positioned over the rod 124, aplatform 163 within the cap 160 contacts the top of the rod 124. Theplatform 163 positions the cap 160 at the end of the rod 124 andprevents the cap 160 from sliding down the rod 124.

A plurality of arms 165 connect the platform 163 and bottom portion 161of the cap 160 to an annular top portion 167 of the cap. Between thearms 165 of the cap are openings which permit fluid to flow through thecap 160. The annular top portion 167 also allows fluid to flow to thesprinkler head 162 without interference from the cap 160. When the cap160 is positioned atop the rod, is generally normal to the rod 124. Theannular top portion 167 has an outer diameter which is smaller than theouter diameter of the riser 16. Thus, the top portion 167 of the cappositions the cap 160 outside the riser 16 so that the cap 160 does notslide within the riser 16. An inner diameter of the top portion 167 islarger than an opening 169 in a sprinkler or other delivery deviceattached to the riser 16, as best shown in FIGS. 19a and 19 b. Fluid canthus flow through the cap 160 from the riser 16 to the sprinkler 162.

In the illustrated embodiment, the cap 160 is a separate piece from therod 124 and can be connected to the rod 124 after the rod has been sizedto fit within a particular riser 16. That is, during installation of thevalve 120 within an irrigation system or other fluid delivery system,the length of the rod 124 can be adjusted to fit within a riser 16 ofany length, such as by breaking off a portion of the rod or stacking aplurality of rods or rod sections. The cap 160 can then be attached tothe top end of the rod 124.

As shown in FIGS. 19a and 19 b, during normal flow conditions, the cap160 contacts the lower portion of the sprinkler head 162. While in theillustrated embodiment, the cap is shown gently biased against the lowerportion of the sprinkler head 162, the cap 160 may also be sandwichedbetween the sprinkler head 162 and the top of the riser 16.

FIGS. 19a-b illustrate the connection between two types of sprinklerhead 162 and the riser 16. FIG. 19a illustrates the top portion of theriser 16 connected to a sprinkler head 162a which is internallythreaded. In this embodiment, a top portion of the riser 16 is threadedexternally and mates with the internal threads of the lower portion ofthe sprinkler head 162 a.

FIG. 19b illustrates the riser 16 coupled to a sprinkler head 162 b,which is externally threaded, through a connector 164. The externalthreads of the riser 16 cooperate with the internal threads of the lowerportion of the connector. In addition, the upper portion of theconnector 164 is internally threaded and cooperates with the externalthread of the sprinkler head 162 b.

As described above, during normal operation, water flow through thebranch passage 38 into the riser 16 is restricted by the sprinkler head162. The rod 124 prevents the stopper 126 from rising in the branchpassage 38 toward the valve seat 138.

When system failure occurs, such as when the riser 16 is broken or asprinkler head 162 is removed, the rod 124 will be carried out by thefluid flow through the riser 16 because the sprinkler head 162 no longerholds the rod 124 in place. Generally, when the riser 16 breaks, the rod124 within the riser 16 will also break. In this case, the remainingportion of the rod 124 is carried out of the riser 16 by the fluid flow.To facilitate this action, the rod 124 may be made from low densitymaterial, such as, for example, but not limited to, polyethylene.

The difference in pressure within the branch passage 38 after the riser16 is broken causes fluid to rush through the branch passage 38 andpushes the remaining portion of the rod 124 upward so that it no longerholds the stopper 126 a distance beneath the valve seat 138. Since therod 124 is no longer holding the stopper 126 in place, the stopper 126can move toward the valve seat 138.

It is believed that one or more of the following factors contributes toor accounts for the stopper's movement toward the valve seat 138. Underabnormal conditions, the fluid flow through the branch passage 38increases. This increase in fluid flow creates a pressure differentialin the areas above and below stopper 126. The flow of fluid from thehigh pressure zone beneath the stopper 126 to the low pressure zoneabove the stopper 126 creates an upward force upon the stopper 126. Inaddition, the opening 133 in the lower portion of the basket is believedto facilitate a flow of fluid from the high pressure zone beneath thestopper 126 toward the valve seat 138. Friction, momentum and/or drag onthe stopper 128 may also contribute to the stopper's movement toward thevalve seat 138.

Because the diameter of the stopper 126 is larger than the diameter ofthe valve throat 144, the stopper 126 generally inhibits the fluid flowthrough the valve throat 144, thereby substantially sealing the valveseat 138.

As described in connection with the embodiments shown in FIGS. 1-13, atelltale stream of fluid desirably is allowed to bypass the stopper 126while the stopper is seated against the valve seat 138. In theillustrated embodiment, fluid escapes through the notches 146 formedalong the inner portion of the ridge 142 of the valve cap 122.

Due to the fluid pressure within the fitting 144 and the small size ofthe telltale ports 146, a small volume of water escapes with highvelocity, such that a telltale stream, or thin fountain of water havingconsiderable height, is produced. Other than the telltale stream, thestopper 126 seated against the valve seat 138 substantially seals theupper receptacle 136 of the valve cap 122 from fluid flow. While thevolume of fluid of the telltale stream is small enough so as not toproduce flooding or erosion, the telltale stream provides for remotedetection of a broken riser or closed valve 120.

FIGS. 21-27 illustrate an additional embodiment of the flow controlvalve. This embodiment is similar to the embodiment illustrated anddescribed in connection with FIGS. 14-19, except that the valve seat andthe basket of the valve cap have been incorporated into the fitting.That is, the valve seat and the basket are placed within the fittingrather than in or attached to a valve cap that cooperates with thefitting. Like components between these embodiments are identified bylike reference numeral, and the above description of these commonelements is to be understood as applying equally to the presentembodiment, unless indicated otherwise.

The valve 190 of this embodiment includes a valve seat member 131instead of the valve cap 122. Similar to the embodiment shown in FIGS.14-19, the device also includes a rod 124, a basket 192 which isattachable to the valve seat member 131, and a stopper 126 which sitswithin the basket 192. The basket 192 differs slightly from the basket128 of the previous embodiment, as will be described below.

With reference to FIGS. 22 and 23, the valve seat member 131 includes agenerally annular upper portion 170 and three legs 172 which depend fromthe upper portion 170. In the illustrated embodiment, the upper portion170 is externally threaded so that it can be installed or screwed withina conventional T-fitting 140 of an irrigation system. It is understood,however, that other methods of joining the valve seat member 131 to thefitting 140 (e.g. adhesive bonding, ultrasonic welding, etc.) are alsopossible. The outer perimeter of the valve seat member 131 needs to besized and shaped to fit within the fitting 140.

In a conventional fluid delivery system, a riser 16 is coupled to theeffluent port of a conventional T-fitting 140. Generally, there is aslight space between the riser 16 and the fitting 140 when the riser iscoupled to the fitting. In one embodiment, the space is about two andone-half threads. The size of this space may vary, however, depending onthe coupling between the riser 16 and the fitting 140. The valve seatmember 131 of the present embodiment is desirably sized and shaped tofit within this opening beneath the riser 16. Thus, the upper portion170 of the valve seat member sits within a conventional T-fittingwithout increasing height of the riser or sprinkler.

The inner surface of the upper portion 170 of the valve seat memberdefines the valve seat 194. The valve seat 194 is configured asdescribed above in connection with FIGS. 14-19. The valve seat 194 has adiameter less than the diameter of the stopper 126. The diameter of thevalve seat is also less than the diameter of the main passageway 34 orthe branch passageway 38. The stopper 126 seats against the valve seat194 under abnormal flow conditions to substantially arrest fluid flow.

In addition, as illustrated in FIG. 22, the inner surface of the upperportion 170 can have notches 174 which cooperate with an instrument tofacilitate the rotation and insertion of the valve seat member 131 andbasket 192 within the fitting 140.

Each leg 171 of the valve seat member includes a foot portion 172 whichis shaped to couple the basket 192 to the valve seat member 131. Thus,in the illustrated embodiment, the foot portion 172 includes a tang thatextends outward from the bottom of each leg 171.

With reference to FIGS. 24 and 25, the basket 192 includes an upperportion 196 and a lower portion 198. The lower basket portion 198 issimilar to the lower basket portion 132 as described in connection withthe embodiment of FIGS. 14-19.

The upper portion 196 of the basket is configured to cooperate with andcouple to the valve seat member 131. In the illustrated embodiment, theupper basket portion 196 has a generally annular shape with an inner andan outer diameter. The inner diameter is larger than the valve seat andthe outer diameter is smaller than an outer diameter of the valve seatmember 131.

In the illustrated embodiment, the inner diameter includes three reliefs176. The reliefs 176 are positioned around the inner diameter to matchthe position of the legs 171 of the valve seat member 131. The legs 171and foot portions 172 of the valve seat member cooperate with thereliefs 176 of the upper basket portion 196 to couple the basket 192 tothe valve seat portion 131. The foot 172 includes a chamfered lower edgewhich allows the upper portion 196 of the basket to easily slide overthe foot 172 during assembly (the legs 171 deflect inward during thisprocess) while the foot portion 172 retains the upper basket portion 196when assembled. The cooperation between the reliefs 176 of the upperbasket portion 196 and the legs 171 prevent rotational movement of thebasket 192 in relation to the valve seat member 131. In othervariations, the upper basket portion 196 may be coupled to the valveseat member 131 by other means, such as adhesives, bonding, or otherknown methods of affixation.

As discussed above, the valve can be integrated into any of a variety ofjunctures. For example, FIG. 26 illustrates the fluid flow control valveof this embodiment within a T-fitting 140 and FIG. 27 shows the fluidflow control valve of this embodiment within an elbow fitting 200.

The operation of the valve 190 of this embodiment is the same as thatdescribed above in connection with FIGS. 14-19.

The valve of the illustrated embodiment thus easily integrates into aconventional fitting of a fluid delivery line without increasing thesize of the fitting or increasing the spacing between the fitting and abranch passage assembly (e.g. raising the height of a riser andsprinkler assembly). It also partakes of the above-noted advantages ofminimal head loss, durability due to a design which eliminatesclose-fitting parts, and exhibits self-cleaning. Additional advantagesof the present design are noted below.

FIGS. 28-30 illustrate another embodiment of the flow control valve.This embodiment is similar to the embodiment illustrated and describedin connection with FIGS. 1-10, but additionally includes the rod 124shown and described in connection with FIGS. 14-19. The abovedescriptions of the elements of the valve 10 of FIGS. 1-10 and the rod124 of FIGS. 14-19 are incorporated in the description of thisembodiment. Similar reference numerals are used for correspondingelements from the above embodiments. A portion of the rod 124 ispositioned through the valve throat 64 and within branch passage 38 ofthe fitting 26.

The operation of the valve 10 of this embodiment is described above inconnection with FIGS. 1-10. In addition, a keeper or rod 124 preventsthe stopper 28 from prematurely seating against the valve seat 64 undernormal flow conditions. For instance, during initialization of thesystem, the stopper 28 may become entrained in the fluid flow and becarried toward the valve seat, even though an abnormal fluid conditiondoes not exist. The rod 124 prevents the stopper 28 from seating againstthe valve seat during this initialization process.

As illustrated in FIG. 29, under abnormal fluid conditions, the rod 124is forced out of the fitting 26, cap 30 and riser 16 by the increasedfluid flow. As described above, the disc 125 at the end of the rod issmall enough to fit through the valve throat 64, thereby allowing therod 124 to completely exit the fitting 26. Once the rod 124 iscompletely pushed out of the fitting 26 and cap 30, the stopper 28 canseat against the valve seat 58 to substantially close the valve 10 (FIG.30) and arrest fluid flow through the valve.

As shown in FIG. 31, the fitting 26 and the cap 30 of the flow controlvalve shown in FIGS. 28-30 can be unitary. Using a compound moldingprocess known to those skilled in the art, the fitting 26 ismanufactured with the stopper 28 confined within the cavity 40. Althoughnot shown in FIG. 31, a rod or keeper 124 similar to that described inthe text above can be used with this embodiment to prevent prematureseating of the stopper 28 against the valve seat 58.

FIGS. 32-38 illustrate a fluid flow control valve 230 in accordance withanother preferred embodiment of the present invention. For ease ofdescription, similar features are ascribed the same reference numeralused for corresponding elements from the embodiments of FIGS. 14-19.Similar to the embodiments described above, this valve 230 can beintegrated into any of a variety of types of junctures. For instance,the valve 230 can be used in a preexisting T-junction, elbow junction orcorner junction in an irrigation system.

With initial reference to FIGS. 32 and 33, the valve 230 includes astopper or stopper device 232 and a valve seat device 234. The valveseat device 234 has an inner diameter which defines a valve seat 256 anda valve passage 250 therethrough. A portion of the stopper 232 fitsthrough the valve passage 250, as illustrated in FIG. 33. Similar to theembodiment shown in FIGS. 14-19, this valve 230 also includes one ormore rods 124 which assist in positioning the stopper 232 to allow fluidflow through the valve passage 250 under normal flow conditions.

As shown in FIG. 34, the valve seat device 234 has an annular shape withan inner and an outer diameter. In the illustrated embodiment, the outerdiameter of the valve seat device 234 is externally threaded 248 so thatthe valve seat device 234 can be screwed into a branch passage port ofthe T-fitting 140. The inner diameter of the valve seat device 234defines a valve passage 250. The inner diameter of the valve seat device234 further includes an upper chamfer or facet 252 and a lower chamferor facet 256. The upper chamfer 252 is sized and shaped to receive anupper stem portion 240 of the stopper 232. The lower chamfer 256 definesthe valve seat.

In the illustrated embodiment, the valve seat device 234 includes aplurality of blind holes 244 spaced along the top side of the valve seatdevice 234. These holes 244 are sized and positioned on the valve seatdevice 234 to cooperate with an assembly tool. Thus, during assembly,the tool can be inserted into these holes 244 to rotate the valve seatdevice 234 within the T-fitting 140 in order to position the valve seatdevice 234 within a branch passage of the T-fitting 140. While in theillustrated embodiment, the holes 244 do not extend through the valveseat device 234, in other embodiments these holes 244 may extend throughthe entire valve seat device 234.

The valve seat device 234 further includes a telltale port 246 whichextends through the valve seat device 234. The diameter of this port 246is substantially smaller than the diameter of the valve passage 250. Thetelltale port 246 allows some fluid flow between the influent port andthe effluent port of the fitting, even when the valve is in a closedposition. The port allows a fine stream of fluid to flow between theinfluent and effluent ports, even when the valve 230 is in a closedposition. This stream of fluid provides an indication that a faultcondition has occurred and also provides some irrigation to thesurrounding area.

With reference to FIG. 36, the stopper 232 includes a stem 236 and avalve element or plug 238. A portion of the stem 236 has across-sectional size which is smaller than the diameter of the valvepassageway 250. This allows the stopper 232 to pass through the valvepassage 250 and also provides for relative movement between the stopper232 and the valve seat device 234.

In addition, the stem portion 236 of the stopper 232 has an upper flaredportion 240. The smallest cross-sectional size of this upper stemportion 240 is the same as the cross-sectional size of the portion ofthe stem which fits within the valve passageway 250. The largestcross-sectional size of the stem flared portion 240, however, is largerthan the diameter of the valve passage 250.

The smallest diameter of the upper chamfer 252 of the valve seat device234 is smaller in size than the diameter of at least a portion of theupper stem portion 240. While the upper stem portion 240 of the stoppercan rest just atop the facet 252, the stopper 232 is not able tocompletely pass through the valve passage 250. That is, thecross-sectional size of the flared stem 240 is larger than the diameterof the valve passage 250. Thus, the upper portion of the stem 240 cannotpass through the valve passageway 250, except during manufacture orunder extreme conditions. In this manner, the stem portion 236 of thestopper prevents the plug 238 from being positioned more than a maximumdistance away from the valve seat device 234 or valve seat 256 undernormal flow conditions.

The stem 236 of the stopper (including the upper portion 240) desirablyhas a cross-sectional shape like a plus sign symbol (+), as bestillustrated in FIG. 37. Other cross-sectional shapes of the stem portionare also possible, such as, but not limited to, circular. The plus signcross section allows fluid to flow between the fins 242 of the stem andthrough the valve passage 250 even while the upper stem portion 240 isseated atop the valve seat device 234.

In the illustrated embodiment, the stopper 238 or bottom portion of thestopper 232 is shaped generally like a spherically-shaped ball. Thestopper, of course, can have other shapes, such as, for example,disc-like, conical, square, elliptical, and the like. The stem portion236 and plug 238 of the stopper 232 can be integrally formed. While thesize of the cross-section of the stem portion 236 is generally smallerthan the size (e.g. diameter) of the valve passage 250, the diameter ofthe plug 238 is larger than the diameter of the valve passage 250. Inthis manner, once assembled, the plug 238 is not able to fit through thevalve passage 250 of the valve seat device 234. Thus, the valve seatdevice 234 and the stopper 232 are interrelated, yet unaffixed orunattached to one another.

For instance, the stopper 232 is generally floating within the fitting140 in that neither the stem 236 nor the stopper 238 is attached, fixedor mechanically secured to the fitting 140 or any other structure. Inthis regard, the stopper 232 is described as floating, even thoughduring normal flow conditions, the biasing device 124 restricts movementof the stopper 232, thereby preventing the plug 238 from prematurelyseating against the valve seat 256.

With reference to FIG. 33, a biasing device or rod 124 is positionedwithin a riser 16 directly above the stopper 232. The rod 124 isconstructed in accordance with the above description, except that inthis embodiment, the rod 124 does not include a disc foot. One way toachieve this is to shorten the rod 124, as described above, by breakingoff a portion of the rod with the foot. In addition, in the embodimentillustrated in FIG. 33, a portion of one set of fins are also broken offfrom the rod 124. The fins 158 aid in positioning the rod 124 in theriser 16 so that the rod 124 is generally centered. Therefore, even ifthe cross-sectional shapes of the rod 124 and the stopper 232 are notexactly aligned, at least a portion of the rod 124 will contact thestopper 232 to prevent plug 238 from prematurely seating against thevalve seat 256. The rod 124 can also be sized to fit with risers 16 ofvarying lengths.

The stopper 232 is positioned through the valve passage 250 of the valveseat device 234 during manufacture of the valve. The stopper 232 and thevalve seat device 234 can be made from different types of materials. Forinstance, plastics of different shrinkage factors can be used to makethe valve seat device 234 and the stopper 232. During manufacture of thestopper 232 and the valve seat device 234, both components are fairlypliable prior to the plastic material cooling completely. Thus, duringthis time, although the size of the valve passage 250 is slightlysmaller than the size of the plug 238, the material comprising the plug238 and/or valve seat device 234 will temporarily deform to allow theplug 238 to pass through the valve passage 250. Upon cooling, however,because of the different shrinkage factors of the respective material,the size of valve passage 250 shrinks to a greater degree than the sizeof the plug 238. Thus, the plug 238 can longer fit through the valvepassage 250. In this manner, the stopper 232 is able to fit through thevalve passage 250 during manufacture, but thereafter cannot pass throughthe valve passage 250, except under extreme conditions. Such extremeconditions do not include normal flow conditions or generally evenabnormal fluid conditions, as described above. Rather, an extreme amountof force is necessary for the stopper 232 to completely pass through thevalve seat device 234.

The valve 230 is designed to resist failure under a designed maximumflow rate and at a designed pressure for a given application.Preferably, the design also incorporates a safety factor. For instance,the valve 230 can be designed, by the selection of relative size andmaterials for the valve seat device 234 and the stopper 232, for arating of 400 psi with a safety factor of 1.5 (i.e. the plug is notforced through the valve seat 256 when the pressure is under 600 psi).Similarly, the size and material of the valve seat device 234 andstopper 232 are such that the stopper 232 remains generally below thevalve seat 256 and in the main passage while being subject to aparticular design maximum flow rate. An exemplary embodiment, forinstance, the valve can be designed to function within a system subjectto a flow rate of 10 gallons per minute through a one inch pipe, yetwill be designed to withstand flow rates up to 15 gallons per minutethrough such system.

The valve is easy to assemble, even within an existing fluid deliverysystem. The stopper 232 and valve seat device 234 assembly of the shownembodiment can be positioned within a fitting 140 of a fluid deliverysystem by screwing the valve seat device 234 within a branch passage ofthe fitting 140. A riser 16 of the fluid delivery system can then bepositioned or screwed within the branch passage of the fitting 140 aswell, just above the valve seat device 234. One or more rods 124 areplaced within the riser 16 so that the upper stem portion 240 of thestopper seats against the upper chamfer 252 of the valve seat device234. In this manner, in the illustrated embodiment, a portion of theplug 238 is generally within main fluid passageway of the fitting 140.

Under normal flow conditions, fluid flows through the T-fitting 140 andinto the branch passage of the riser 16. The rod 124, which sits atopthe stopper 232, restricts movement of the stopper 232 and prevents theplug 238 from prematurely seating against the valve seat 256. When anabnormal flow condition occurs, however, the rod 124 is carried out bythe fluid flow through the riser 16. As the rod 124 no longer holds thestopper 232 in place, the plug 238 can move toward the valve seat 256.Movement of the stopper 232 is facilitated by the rush of water throughthe branch passage of the fitting 140 since the fluid flow through thevalve passage 250 is no longer restricted by the sprinkler head 162.Because the plug 238 is larger than the valve passage 250, the plug 238generally inhibits fluid flow through the valve passage 250, therebysubstantially sealing the valve seat 256.

As described in connection with the embodiment shown in FIGS. 1-19, atelltale stream of fluid desirably is allowed to bypass the stopper 238while the stopper 238 is seated against the valve seat 256. In theillustrated embodiment, fluid escapes through the telltale port 246formed through the valve seat device 234.

The valve seat device 234 and the fitting 140 of the flow control valveshown in FIGS. 32-38 can be unitary, as shown in FIG. 38. The abovedescriptions of the elements of the valves described above areincorporated in the description of this embodiment. Similar referencenumerals are used for corresponding elements from the above valves. Asis true with the embodiment described above in connection with FIGS.32-38, the fitting 260 can include vanes 48, such as those describedabove, to aid in the laminar flow of fluid within the fitting 260. Theoperation of the flow control valve 260 shown in FIG. 39 is similar tothat of the valve shown in FIGS. 32-38.

FIGS. 40 and 41 illustrate a fluid flow control valve or check valve 270in accordance with another preferred embodiment of the presentinvention. The above descriptions of the elements of the valve 230 ofFIGS. 32-39 are incorporated in the description of this embodiment. Forease of description, similar features are ascribed the same referencenumeral used for corresponding elements from the above embodiments.Similar to the embodiments described above, this valve 270 can beintegrated into any of a variety of types of junctures or fittings. Forinstance, while the valve 270 is shown in FIGS. 40-41 in a generallystraight pipe fitting, the valve 270 can be used in an elbow junction orcomer junction in an irrigation system.

The valve 270 includes a fitting 272 having an influent port or firstport 274, an effluent port or second port 276, a valve seat 282 betweenthe influent and effluent ports 274, 276, and a stopper 232. A firstpassageway 278 extends from the influent port 274. A second passageway280 extends from the effluent port 276. The first passageway 278 and thesecond passageway 280 are in fluidic communication with each other. Inthe embodiment shown in FIGS. 40 and 41, the first and secondpassageways are coaxial to each other, or are parallel to one another.In other embodiments, the first and second passageways 278, 280 can beoriented relative to one another at various angles, such as, but notlimited to a 90° angle.

The valve seat 282, which is between the first passageway 278 and thesecond passageway 280, defines a valve passageway 284. The valve seat282 is similar to the valve seat 256 described above in connection withFIGS. 32-39.

The stopper 232 is constructed in accordance with the above descriptionof the stopper in connection with the embodiment shown in FIGS. 32-39.In addition, the positioning of the stopper 232 through the valvepassageway 284 of the fitting 272 is achieved by the method ofmanufacture described above.

The present fluid flow control valve also provides a flow straighteningeffect within the fluid flow through either the primary passage or thebranch passage, or both. For example, the fins of the rod 124 are shapedand sized to provide a flow straightening effect in fluid flow throughthe riser. Additionally, the vanes 48 provide a flow straighteningeffect in fluid flow through the effluent port 24.

The present fluid flow control valve also can withstand system shock,such as water hammer when the system is turned on or off. For instance,in connection with the valve design illustrated in FIGS. 14-19, systemshock is absorbed and transferred by the basket to the housing andfitting. In addition, the placement of the basket within the primarypassage of the irrigation system fitting minimizes head loss within thebranch passage and to the sprinkler. Yet, this placement of the basketdoes not restrict fluid flow in the primary passage since fluid can flowthrough the openings of the basket. Further, the valve designillustrated in FIGS. 32-39 can withstand system shock and drag forces,as discussed above.

FIG. 40 illustrates the check valve 270 under normal operatingconditions. The arrows shown in FIG. 40 indicate the direction of flowthrough the fitting 272 under normal operating conditions, i.e. when thedirection of fluid is from the first port 274 toward the second port276. Under normal conditions, the stopper 232 is in an open position.That is, the valve element 238 is positioned a distance away from thevalve seat 282, and fluid can flow through the valve passageway 284.

The check valve 270 prevents fluid from flowing through the valvepassageway 284 under closed conditions, such as after the irrigationsystem is turned off. For instance, in an irrigation system on ahillside or mountain, fluid flows uphill when the fluid source is turnedon, i.e. when pressurized. When the fluid source is turned off, however,gravity (i.e. the fluid head) forces the fluid within the system to flowback toward the fluid source. The fluid flow control valve 270 preventsfluid within the system from flowing in a direction opposite the normalflow within the system. Thus, the valve 270 prevents an undesirablereverse flow within the irrigation system.

FIG. 41 illustrates the fluid flow control valve 270 in a closedposition. The arrows in FIG. 41 indicate the direction of fluid flowwithin the fitting 272 from the second port 276 toward the first port274. When fluid flows in such a direction, the stopper 232 is moved to aclosed position, such that the valve element 238 seats against the valveseat 282. Thus, fluid through the valve passageway 284 is arrested.

The check valve 270 can be easily integrated into existing irrigationsystems. For instance, in the illustrated embodiment, the influent port274 and the effluent port 276 of the fitting 270 are sized to eachreceive an irrigation pipe 288, 290 of the existing system. The influentand effluent ports 274, 276 of the fitting 272 can also be threaded toreceive a threaded portion of an irrigation pipe.

In the illustrated embodiment, the valve seat 282 is unitary with thefitting 272. In other embodiments, the valve seat 282 can be held inplace within the fitting 272 by other means, including, but not limitedto ultrasonic welding, adhesives, bonding, threaded engagement, andother known methods of affixation.

FIGS. 42-44 illustrate a fluid flow control valve 300 in accordance withanother embodiment of the present invention. This embodiment issubstantially similar to the embodiment illustrated and described inconnection with FIG. 40-41, except that the stopper 302 includes a valvesealing device 308 around the valve element 306 and the valve seat 282includes a stopper positioning device 308. In addition, in theembodiment shown in FIG. 42, the valve seat 282 is not unitary with thefitting 272. For ease of description, similar features are ascribed thesame reference numeral used for corresponding elements from theembodiment of FIGS. 40-41, with the understanding that the abovedescription of the similar feature is to apply equally to the presentembodiment, unless otherwise indicated.

Similar to FIG. 41, FIG. 42 illustrates the fluid flow control valve 300in a substantially closed position. The stopper 302 includes a stem 304,a valve element 306, and a valve sealing device 308. The valve element306 has a recess 312 into which the valve sealing device 308 fitssnugly. The outer shape of the valve sealing device 308 desirablycomplements the shape of the valve element 306, i.e., in the illustratedembodiment, the valve element 306 with the valve sealing device 308fitted thereon has a spherical shape. In a preferred embodiment, thevalve sealing device 308 is made from rubber, although other materialscan also be used. The stopper 302 of the embodiment shown in FIGS. 42-44can be used in any of the valves described above or below.

In the illustrated embodiment, the stopper positioning device 310 isunitary with the valve seat 282. The stopper positioning device 310,which is cylindrical in shape, extends away from the valve seat in anopposite direction from the valve element of the stopper and serves as aguide to center the stopper 302 within the valve passageway 284. Thus,the diameter of the stopper positioning device 310 is slightly greaterthan the diameter of the stem 304 of the stopper. When fluid flowswithin the fitting 272 in a direction from the second port 276 towardthe first port 274, the stopper 302 is moved to a closed position, asillustrated in FIG. 42. Because the stem 304 is centered within thestopper positioning device 310, the valve element 306 is likewisecentered within the valve passageway 284. The valve element 306 seatsagainst the valve seat 282 and the softer material of the valve sealingdevice 308 forms a tight seal with the valve seat 282, therebypreventing or substantially restricting fluid flow through the valvepassageway 284.

During manufacture of the valve 300, the valve element 306 of thestopper 302 is pushed through the valve passage 284 of the valve seat282. This may be done in accordance with the method of constructiondescribed above. The valve sealing device is passed over the valveelement 306 to fit within the recess 312 of the valve element 306. Thevalve 300 is then ready for positioning within and for securing to thefitting 272, such as, for example, but without limitation, by ultrasonicwelding, adhesives, bonding, threaded engagement, or other methods ofaffixation. The assembly of the fluid flow control valve is eased byassembling the stopper 302 and the valve seat 282 before positioning andattaching the valve seat 282 at a location within the fitting 272. It isunderstood though that the valve seat 282 can be unitarily formed withinthe fitting 272 or can be positioned and attached to the fitting beforeinserting the valve element 306 of the stopper 302 through the valveseat 282.

FIGS. 45-51 show a fluid flow control valve within a pop-up sprinkler411. The fluid flow control valve 400 within the pop-up sprinkler 411substantially arrests the flow of fluid through the sprinkler head 429when the riser 415 is broken or the sprinkler head 429 is removed.

The pop-up sprinkler 411 generally includes a housing 413, a movableriser 415, a positioning ring 417, a spring 419, a filter 421, a housingcap 427, and a sprinkler head 429. As illustrated in FIG. 45, the riser415, positioning ring 417, spring 419, and filter 421 are situatedwithin the housing 413 when the system is not in use. The upper end ofthe housing 413 is attached to the cap 427 by threads 425, therebyclosing the upper end of the housing. The lower end of the housing 413has an inlet 423 coupled to a supply conduit (not shown) of theirrigation system via a conventional fitting and nipple.

As best seen in FIG. 46, the riser 415 is a tube having an inner wall433 defining an axially extending, cylindrical passage 435 which extendscompletely through the riser 415. An integral flange 437 is provided atthe lower end of the riser 415. The upper end of the riser 415 isattached to the sprinkler head 429. In an exemplary embodiment, both thehousing 413 and the riser 415 are molded from suitable polymericmaterials; however, these components can be formed of a wide variety ofother materials, as will be appreciated by those skilled in the art.

In the illustrated embodiment, the riser 415 includes an annular ring440 which is unitary with the riser 415. The ring 440 provides anabutment against which a valve seat device 434 is positioned. In othervariations, however, the valve seat device 434 can be secured within theriser 415 by known methods of affixation, or can be integrally formed(i.e., unitary) with the riser tube 415.

The filter 421 is positioned just below the sprinkler head 429. Thefilter 421 has a plurality of small openings to allow fluid to flowthrough it from the riser 415 to the sprinkler head 429, whilesubstantially preventing dirt or other debris from being carried to thesprinkler head 429. Because the sprinkler head 429 has only a smallopening through which fluid from the irrigation system is dispensed,even a small amount of debris from the irrigation system can easily clogthe sprinkler head 429 and alter its spray pattern (both radially andcircumferentially) and/or affect or reduce the flow rate through thesprinkler.

In the illustrated embodiment, the filter 421 includes a flange 441 atits upper end. The flange 441, which is integrally formed with thefilter 421, sits atop a threaded portion 439 of the riser 415 and belowthe sprinkler head 429, when the pop-up sprinkler is assembled. Thus,the flange 441 is wedged between the sprinkler head 429 and the riser415, thereby assisting in positioning the filter 421 within the riser415. In other variations, however, the filter 421 can fit loosely withinthe riser 415. The filter 421 can be positioned within the riser 415 inother ways, including but not limited to, being positioned within theriser by the rod 424, which is sized to fit between the filter 421 andthe stopper 432.

In the illustrated embodiment, the lower end of the filter 421 isunitary with the rod 424. The rod 424 is similar to the rod 124 shownand described above in connection with the embodiment of FIGS. 14-19;however, the rod 424 shown in this embodiment is slightly tapered fromthe point where it is attached to the filter 421 to the positioning fins458 at its lower end. Unlike the rod 124 described above in connectionwith other embodiments, the rod 424 is presized to extend to the stopper432 when assembled (as shown in FIG. 45) to prevent closure of thevalve. The rod 424 thus need not include one or more grooves 154 whichwould provide a break point in the rod. The fins 458 assist inpositioning the rod 424 so that the rod 424 is generally centeredrelative to a stem 436 of a stopper 432.

The riser 415 is movable from a retracted position, in which the riseris closely adjacent the inlet 423 and the sprinkler head 429 is flushwith the upper end of the cap 427 (shown in FIG. 46), to an extendedposition, in which the riser 415 extends from the housing 413 so thatthe sprinkler head 429 is a distance away from the upper end of the cap427 (shown in FIG. 47) in response to water pressure built within thehousing when the irrigation system is in use. When the sprinkler is inuse, fluid under pressure is supplied by the supply conduit of theirrigation system through the housing inlet 423. Although the spring 417acts to bias the riser 415 toward the retracted position, the waterpressure within the housing 413 acts on the riser to move the riser 415against the biasing action of the spring 417 from the retracted positionto the extended position. This enables the sprinkler head 429 to rise toa predetermined heighth to broadcast water to the surrounding area.

The fluid flow control valve 400 is similar to the embodiment shown inFIGS. 32-38. The valve 400 comprises a stopper 432, a valve seat member434, and a rod 424. The above description of similar elements is to beunderstood to apply equally to the present embodiment, unless otherwiseindicated. In the illustrated embodiment, however, the valve seat member434 is not externally threaded, and instead is held in place within theriser 415 by adhesives, ultrasonic welding, bonding, or other knownmethods of affixation. Similar to the valve seat member shown in FIG.37, the valve seat device 434 can also be threaded and situated withinan internally threaded riser 415 by threaded engagement.

The operation of the valve 400 of this embodiment is similar to thatdescribed above in connection with FIGS. 32-38. When the riser 415 isbroken or the sprinkler head 429 is removed, the sprinkler head 429 nolonger holds the filter 421 and rod 424 in place, and the filter 421 androd 424 are carried out of the riser 415 by the water flow. Because therod 424 no longer holds the stopper 232 in place, the valve element 438can move toward the valve seat 256, thereby substantially sealing thevalve seat 256.

As described in connection with the embodiment shown in FIGS. 1-19, atelltale stream of water desirably is allowed to bypass the stopper 432when the valve element 438 is seated against the valve seat 256. Asillustrated in FIG. 48, a small amount of water escapes through thetelltale port 146 formed through the valve seat device 434.

As illustrated in FIGS. 45, 47 and 48, the valve seat member 434 ispositioned within the housing when the riser is in both the retractedand expanded positions. Therefore, if the riser is broken at a locationabove the housing cap 427, the stopper 432 and valve seat member 434remain intact and the valve 400 can substantially close to prevent fluidflow through the riser 415.

As illustrated in FIGS. 49-51, in other variations, the rod 124 can beformed separately from the filter 421, such as but not limited to, avalve retrofit within an existing pop-up sprinkler. The rod 124, whichis constructed in accordance with the description of the rod inconnection with FIG. 33, is positioned between the filter 421 and thestopper 432. The rod 124 can be sized to fit within the riser 415 in avariety of ways, including, but not limited to those discussed above.While grooves 154 along the rod 124 enable a portion of the rod 124 tobe easily snapped off, and the spring 156 compensates for manufacturingtolerances of the length of the rod 124, in other variations, the rod124 can be formed without the grooves 154 and/or the spring 156. Forinstance, the rod 124 can be presized to fit within a riser of apredetermined length.

The fluid flow control valve 400 can be provided, such as in a kit, tobe retrofit within an existing pop-up sprinkler. Such a kit includes thestopper 432, the valve seat member 434, and one or more rods 124. Thekit can designate a pop-up sprinkler of a particular size into which thevalve is to be integrated. A presized rod 124 can be provided in thekit, or the kit can include a plurality of rods which can be sized orused together to fit between the filter 421 and the stopper 432.

At the end of the rod 124 nearest the filter 421, or the upper end ofthe rod 124, are a plurality of fins 158 which assist in positioning therod 124 so that it is generally centered relative to the bottom of thefilter 421. The fins 158 can be integrally molded with the rod 124 orcan be attached to the rod 124, such as by positioning a cap (not shown)over the upper end of the rod 124. The cap does not have to include fins158, but instead can be formed to include a platform or otherpositioning device against which the filter 421 sits.

FIGS. 52-55 illustrate a first valve 500 and a second valve 550 within aswing joint 501 of an irrigation system or other fluid delivery system.The swing joint 501 includes a first fitting 506 in which the firstvalve 500 is positioned and a second fitting 507 in which the secondvalve 550 is positioned.

In FIG. 53, both valves 500, 550 are shown in an open position. Theelements of the first and second valves are substantially similar to oneanother, except that the biasing device in the first valve 500 is a rod124 while the biasing device in the second valve 550 is a spring 552.

The first valve 500 of this embodiment is similar to the valve 230 shownand described in connection with the embodiment of FIGS. 33-38. Thesecond valve 550 is also similar to the valve 230 shown and described inconnection with the embodiment of FIGS. 33-38, except that a spring 552is used in place of the rod 124, and a basket or support 504 abuts thespring 552 to prevent the spring 552 from contacting the stopper 232 ofthe first valve. In this manner the basket 504 assists in positioningthe spring 552 within the fitting, in contact with the stopper 232 ofthe second valve 550, just as the sprinkler head assists in positioningthe rod 124 in contact with the stopper 232 of the first valve 500. Likecomponents between the embodiment shown and described in connection withFIGS. 33-38 and the present embodiment are identified by like referencenumeral, and the description of these common elements is to beunderstood as applying equally to the present embodiment, unlessindicated otherwise. Similar reference numbers with the suffixdesignation “a” and “b” are used to refer to similar elements of thefirst valve 500 and the second valve 550, respectively.

The first valve 500 of this embodiment includes a valve seat member 234a, a rod 124, a basket 504 which cooperates with the valve seat member234 a, and a stopper 232 a. The valve seat member 234 a is positionedwithin the first fitting 506 of the swing joint 501 of the irrigationsystem.

Along the top and bottom of the valve seat member 234 a are a pluralityof blind holes or notches 244 which are sized and positioned on thevalve seat member 234 a to cooperate with an assembly tool. The notches244 on the bottom side can be used to position the basket 504 such thatat least part of its lower portion 510 is positioned between the spring552 and the valve element of the stopper 232 a to prevent the spring 552from contacting the stopper 232 a.

The basket 504 includes an upper portion 508 and a lower portion 510.The lower basket portion 510 is similar to the lower basket portion 198as described in connection with the embodiment of FIGS. 24-25, and thatdescription should be understood to apply equally to the presentembodiment. The upper basket portion 508 is configured to cooperate withand couple to the valve seat member 234 a. In the illustratedembodiment, the upper basket portion 508 has a generally annular shapewith a plurality of extensions 512. The extensions 512 are shaped andpositioned around the upper portion 508 to fit within the notches 244 inthe bottom side of the valve seat device 234a to couple the basket 504to the valve seat device 234 a. Thus, the basket 504 and the valve seatdevice 234 a cooperate to rotate the basket to allow one or more arcs ofthe lower portion 510 of the basket to be positioned between the spring552 and the stopper 232 a.

Although the valve element 238 a of the stopper 232 a of the first valve500 of this embodiment is positioned within the basket 504, the basketneed not provide support for the stopper 232 a. Instead, the basket 504principally acts to prevent the spring 552 of the second valve 550 fromresting against the stopper 232 a. Of course, any of a variety of otherstructures can be used to interact with the end of the biasing device soas to prevent the biasing device from contacting the valve element ofthe stopper. For instance, the first fitting can include one or morevanes 48, such as those shown in FIGS. 11-13, which extend from one sideof the fitting to the opposite side, or any type of extension (e.g., apost) within the fitting 506 which prevents the spring 552 from pressingagainst the stopper 232 a.

The first valve 500 operates similar to the valve 230 described inconnection with FIGS. 32-38. The rod 124 prevents the stopper 232 a fromprematurely seating against the valve seat. As illustrated in FIG. 54,after the riser 16 is broken, fluid flow moves the rod 124 away from thestopper 232 a, thereby allowing the stopper 232 a to seat against thevalve seat of the valve seat member 234.

The second valve 550 includes a spring 552, a stopper 232 b, and a valveseat device 234 b positioned within the second fitting 507 of the swingjoint 501. The spring 552, which is positioned between the basket 508 ofthe first valve and the stopper 232 b of the second valve, prevents thestopper 232 b from seating against the valve seat 234 b under normalflow conditions.

The second valve 550 operates in a manner similar to the first valve500. When the fitting 506 is severed between the first valve 500 and thesecond valve 550, the spring 552 expands and the valve element 238 b ofthe stopper 232 b seats against the valve seat to substantially arrestthe flow of fluid through the valve passageway, as illustrated in FIG.55.

Rotation of the first and second fittings 501, 507 of the swing joint501 relative to one another does not affect the operation of the firstand second valves 500, 550, because the positioning of the biasingdevice 552 between the valves is not affected by such movement.

In addition, as common to all of the flow control valves describedabove, the valve can function even if catastrophic failure occurs. Forinstance, because the valve seat and stopper are located within thefitting or the riser, the valve will continue to function, even if theriser breaks off completely from the fitting or the housing containingthe valve seat is severed. For example, even if the valve cap shown inFIG. 14 were severed between first portion 139 and the second portion141, the valve would continue to function since the valve seat 138 andthe stopper 126 are undamaged. Further, in the embodiments illustratedin FIGS. 32-39, the valve seat 256 is positioned directly within thebranch passage of the fitting.

The flow control valve is also easy to assemble and integrate withstandard irrigation systems. For instance, the T-fitting 26 can becoupled to the pipes of irrigation system. Further, because the basket,which contains the stopper, is affixed to the valve cap in the designshown in FIGS. 14-19, the cap-basket-stopper assembly can be easilyintegrated into an existing irrigation system by positioning the housingbetween the fitting and riser. Similarly, the embodiment shown in FIGS.32-38 is easy to integrate into an existing irrigation system in thatonly the valve seat device 234 and stopper 232 assembly needs to bepositioned within an existing fitting 140, which can be accomplished bysimply screwing the valve seat device 234 within the fitting 140.Likewise, the embodiment shown in FIGS. 45-51 can easily be integratedinto a pop-up sprinkler by affixing the valve seat device 434 andstopper 432 within the riser 415 and positioning a rod 424 just belowthe filter 421. Thus, the flow control valves described above can beused with a standard available fitting dimensioned and manufactured foruse in commonly used irrigation systems or commonly used pop-upsprinklers.

In addition, the rod or rods 124 are easily sized to fit within riserassemblies of various lengths, including those riser assemblies thatextend several feet or more above the fitting as well as those that formpart of a pop-up sprinkler. If a riser has a length greater than thelength of one rod, a plurality of rods can be stacked atop one anotherso that the rods extend from the stopper, through the riser, and to thesprinkler head. The grooves on the rod allow the rod to be snapped orbroken when a certain amount of force is applied to the groove.Therefore, special tools are not required to size the rod within theriser assembly. Further, the rods do not have to be precisely sized tofit within the riser assembly because the spring of each rod can becompressed to absorb tolerance stack-up within the assembly.

Although the foregoing invention has been described in terms of certainpreferred embodiments, other embodiments will become apparent to thoseof ordinary skill in the art in view of the disclosure herein.Furthermore, the skilled artisan will recognize the interchangeabilityof various features of one embodiment to another embodiment.Accordingly, the present invention is not intended to be limited by therecitation of preferred embodiments, but is intended to be definedsolely by reference to the appended claims.

What is claimed is:
 1. A pop-up sprinkler comprising a housing, a pop-upriser at least partially disposed within the housing and movablerelative to the housing, a valve seat disposed within the riser, astopper cooperating with the valve seat and having a valve element, thestopper being movable between a first position in which the valveelement is located a distance away from the valve seat, and a secondposition in which the valve element sits against the valve seat, and abiasing device which prevents the valve element from seating against thevalve seat under normal flow conditions, the biasing device including anintegral spring configured to allow the effective length of the biasingdevice to vary.
 2. The pop-up sprinkler of claim 1, wherein the biasingdevice comprises a rod.
 3. The pop-up sprinkler of claim 2 additionallycomprising a sprinkler head attached to the riser and a filter betweenthe sprinkler head and the valve seat, the rod being unitary with thefilter.
 4. The pop-up sprinkler of claim 2, wherein the rod includes aplurality of grooves spaced longitudinally along the rod, whereby thegrooves facilitate in breaking off a portion of the rod to size the rodto fit within the pop-up riser.
 5. The pop-up sprinkler of claim 2,wherein the riser includes an annular ring against which the valve seatdevice is positioned.
 6. The pop-up sprinkler of claim 1, wherein thevalve seat is positioned within the housing.
 7. A fluid flow controlvalve for a pop-up sprinkler having a housing and a riser disposed atleast partially within the housing and movable relative to the housing,the fluid flow control device comprising a valve seat device defining avalve passageway the valve seat device sized and shaped to fit withinthe riser, a stopper positioned within the valve passageway, the stopperbeing movable between an open position and a closed position, and abiasing device which biases the stopper toward the open position andprevents the stopper from seating against the valve seat under normalflow conditions, the biasing device including an integral springconfigured to allow the effective length of the rod to vary.
 8. Thefluid flow control device of claim 7, wherein the biasing devicecomprises a rod.
 9. The fluid flow control device of claim 8, whereinthe rod comprises a plurality of grooves spaced longitudinally along therod, whereby the grooves facilitate in breaking off a portion of the rodto size the rod to fit within the riser.
 10. The fluid flow controldevice of claim 7, wherein the stopper includes a compressible sealingmember positioned around a portion of the stopper to seat against thevalve seat when the stopper is in the closed position.
 11. The fluidflow control device of claim 10, wherein the stopper additionallyincludes a valve element, the valve element being located away from thevalve seat when the stopper is in the open position and seated againstthe valve seat when the stopper is in the closed position, and thesealing member is located around a portion of the valve element.
 12. Thefluid flow control device of claim 11, wherein the stopper additionallyincludes a stem portion.
 13. The fluid flow control device of claim 1,wherein the valve seat is unitary with the riser.
 14. The fluid flowcontrol device of claim 7, wherein the stopper includes a valve elementand a stem, the stem having a flared portion, the stopper locatedrelative to the valve seat device such that the flared portion of thestem is located on one side of the valve seat and the valve element islocated on the other side of the valve seat.
 15. The fluid flow controldevice of claim 14, wherein the stopper positioning device iscylindrical in shape and extends away from the valve seat in an oppositedirection from the valve element of the stopper.
 16. The fluid flowcontrol device of claim 14, wherein the diameter of the flared portionof the valve stem is larger than the diameter of a valve passagewaydefined by the valve seat.
 17. The fluid flow control device of claim16, wherein the diameter of the stopper positioning device is slightlygreater than the diameter of the flared portion of the valve stem. 18.The fluid flow control device of claim 7, wherein the biasing device isattached to a filter of the pop-up sprinkler, the filter beingpositioned within the riser.
 19. A fluid flow control valve assemblycomprising a first fitting and a second fitting, the first and secondfittings cooperating with and movable relative to one another, eachfitting having a valve within the fitting, the valve including a valveseat positioned within the fitting and a stopper positioned within avalve passageway defined by the valve seat, the stopper being movablebetween an open position and a closed position, and a biasing devicepositioned between the stopper of the first fitting and the stopper ofthe second fitting, the biasing device biasing at least one of thestoppers in an open position under normal flow conditions.
 20. The fluidflow control valve assembly of claim 19, wherein the first fitting is anelbow fitting.
 21. The fluid flow control valve assembly of claim 20,wherein the second fitting is an elbow fitting.
 22. The fluid flowcontrol valve assembly of claim 19, wherein the biasing device is aspring.
 23. The fluid flow control valve assembly of claim 19, whereinthe biasing device biases the stopper of the second valve in the openposition under normal flow conditions, and additionally comprising asupport which prevents the biasing device from contacting the stopper ofthe first valve.
 24. The fluid flow control valve assembly of claim 23,wherein the support comprises a basket.
 25. The fluid flow control valveassembly of claim 23, wherein the support comprises a post.
 26. A fluidflow control valve within a swing joint of an irrigation systemcomprising a first valve seat device and a second valve seat device,each valve seat device having a valve seat, a first stopper and a secondstopper, the first stopper cooperating with the first valve seat and thesecond stopper cooperating with the second valve seat, each stopperhaving a valve element and a stem, the stem having a flared portion, thefirst stopper being located relative to the first valve seat device suchthat the flared portion of the stem is located on one side of the valveseat and the first valve element is located on the other side of thevalve seat, and the second stopper being located relative to the secondvalve seat device such that the flared portion of the stem is located onone side of the valve seat and the second valve element is located onthe other side of the valve seat, a first biasing device which preventsthe first valve element from seating against the first valve seat undernormal flow conditions, and a second biasing device which prevents thesecond valve element from seating against the second valve seat undernormal flow conditions.
 27. The fluid flow control valve of claim 26additionally comprising a support which prevents the second biasingdevice from contacting the first valve element.
 28. The fluid flowcontrol valve of claim 27, wherein the support comprises a basket. 29.The fluid flow control valve of claim 26, wherein the first biasingdevice comprises a rod.
 30. The fluid flow control valve of claim 26,wherein the second biasing device comprises a spring.
 31. The pop-upsprinkler of claim 1, wherein the stopper includes a valve element and astem, the stem having a flared portion, the stopper located relative tothe valve seat device such that the flared portion of the stem islocated on one side of the valve seat and the valve element is locatedon the other side of the valve seat.
 32. The pop-up sprinkler of claim31, wherein the stopper further includes a compressible sealing memberpositioned around a portion of the valve element to seat against thevalve seat when the stopper is in the closed position.